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WRGKMC last won the day on April 16 2018

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  1. When you use singles with humbuckers its best to use a balanced set so you don't have volume changes switching pickups. If you're picking individual pickups form different makers it can be pure guesswork in what might match because Inductance involves several factors including magnet strengths, wire size, number or wraps, wrap density, and other things like the density/amount of ferromagnetic materials. I've done many match jobs on builds and mod jobs trying to get the best balance and you can waste a lot of time and money trying to get it right. Knowing the DC resistance is often the only thing you have to work with. Very few pickup makers list the actual number of Henry's a coil has or even the magnet type. I've gotten pretty good at getting a balance by using HB's with vintage winds and singles that have slightly hotter winds. Even there I'm lucky enough to have several dozen different sets of pickups in my parts cabs to work with. Mixing and matching can even be done prior to going through the hassle of actually installing them if you have a few simple tools available. What you need is a stereo volume meter. An old cassette recorder is ideal for this. If you have a number of HB's you want to match with existing singles, you can connect the guitar cored to one channel of the recorder, then adjust the record volume to get the meter to read about 50%. Take an old guitar cord and connect it to the leads of whatever pickup you may be considering. If the cord as a bare wire at one end soldering alligator clips to that end is ideal for testing multiple pickups. Lay the guitar on a table face up. Find a corrugated carboard box and cut it up in small pieces maybe 1X2" which can be stacked along side the two E strings and then you can bridge the strings with the pickup. Add or remove the number of cardboard pieces till the pickup matches the distance of a pickup mounted in the guitar. Now you can compare the outputs of the two pickups on the cassette recorder meters and judge whether the two are any kind of a match. You can figure with most pickups mounted in a guitar your distance between pickup and strings is typically set at a minimum of 3mm and maximum of maybe 5mm. Anything farther they usually become a bit thing and less focused. you can use the pieces of cardboard to distance the pickup to try and get a signal strength match. If you wind up having a huge distance then that pickup is likely too hot. I should also mention, the low strings will have a higher output compared to the high strings on those meters as much as double the strength with the string distances even across the strings. That's normal. Guitar amps were built to match pickups and roll off lows and highs to produce mostly midrange tones and make the pickups sound even. Pickups are not built to produce high fidelity tones and when plugged into a high fidelity amp or recorder have boosted highs/lows and scooped mids. When testing you can try each string and see how close each string matches in gain too. I would focus on the first 4 strings for matching strength. HB's typically have more bass output and shouldn't be a big issue so long as the higher strings match in gain. This testing method is better then going through the hassle of installing the pickup and often times routing the body and pickguard to fit it inside, only to discover it was a bad match before you went through that hassle or mounting and wiring it. It also makes you appreciate when manufacturers sell matched sets they've gone through all this testing and you can simply jump to installing the pickup and know its going to work well.
  2. most of the music I listen to is the stuff I write and record. I was a huge audiophile growing up and still have several thousand LP, s Cassettes and CD's I bought over the years. They were my library for learning how to be a musician. I even have the scratches in those old LP's memorized from having lifted and dropping the needle so many times to learn parts. Along with that I used to drive for a living so I'd listen to music 8~10 hors a day in the car driving from one job to the next. When I jam with other people they are mystified how I can memorize and play most of a song after only hearing it one time. They think its some kind of gift. They don't see the lifetime of ear training It took to be able to do that. I guess all those years of listening eventually turned around and started working in the opposite direction. For the past 30 years I write more then I listen to other peoples music and have gotten far away from mimicking other peoples music. If all that listening did have an influence on my writing its well masked at this point. I can mimic other artists at will but I rarely will to do so any more. Its too much like playing cover tunes which I also got bored silly playing in cover bands. I lost count of how many cover tunes I learned to play and become quite bored listening to many of them too. Playing those songs live does that to you. Simply listing has less emotional appeal compared to playing them live and getting a response back. I still enjoy finding offbeat stuff though. Friends used to tell me I had the best B side movie collection out there. In reality, the hits were so over played on the radio it was like fingernails on a chalk board hearing them so I'd find other songs by the same bands people didn't hear as often but were still very good and popular. I used to like listening to stations like PBS that had New Age and various odd forms of music. Some of the other Rock stations would also play great stuff late night early morning when they had few listeners and weren't glued to playing music on the charts. Every so often I'd hear a song I really liked but these days they don't even tell you who the artist or song name was. They aren't interested in selling music or promoting artists. When the internet made stealing songs easy, the stores that sold music collapsed. This dried up all the cash for studios to make money and any artists relying on album sales either switched to live shows as income or tried the on line music sales for a penny a purchase. Good luck with that. This Corona virus is going be the coffin nails for most working bands. No clubs open, no work for bands.
  3. I have two of the newer 15W valve state amps. Ones the older version and one is newer with built in effects. They are actually loud enough to rehearse with a drummer if you use the pair. I mainly use one for practicing in the living room. I can dial it up to a low volume with saturated tones and practice my riffs. I've used both with stereo effects pedals doing acoustic jams. Actually sounds pretty good. Light and portable too. I bought both for under $50 and the amps still sell for incredibly high prices used. Most of the ones you see are either new or close to $100 used.
  4. That's actually not a bad price. Someone could use what they need and sell the rest for a profit. You can get the stuff that's already tinned here for $6 a foot and it goes down in price the more you buy. https://www.ebay.com/itm/3-8-I-D-Braided-Stainless-Steel-Tubular-Sleeve-Wire-Cover-For-Harley-Hot-Rod-/263580011167?_trksid=p2385738.m4383.l4275.c10&var=562631699666 You know I have an old Teisco that uses a flat metal spring as a grounded conduit for the wiring. Its even soldered to the pots for a solid ground. The body didn't have any pickups when I got it but the original pots from the 60's were still good. I simply ran the new wires through the conduits and its still working fine 20 years later. I was thinking, Having three separate braiding conduits under that pickguard does add allot of unnecessary wiring. Its about as overkill as shielding an entire cavity to simply shield one hot wire. All you really need in a Strat is one tube, that extends from the bridge pickup to the controls. The middle and bridge pickup wires can share that same shield. It passes under those pickups and you can simply poke a new hole in the braiding at those points using a pencil to create a hole and feed the additional pickup wires through to the controls. It would surely be a lot neater too. I had to use hot glue to get the 3 sets of braiding to lay flat and manageable in order to get the pickguard back in place. It sure would have been easier and cause less chances of shorting using only one.
  5. Sure, I'll see what I can do for you this week end. I don't do much during the week besides play. I have to pull the pickguard off that Strat this weekend to rewire the pots. I have to remove the neck to get at it because the neck overhangs the pickguard. You'll be able to see how I added braded shielding over the pickup wires to eliminate hum. That braiding is super hard to find. They had some left over at work they were going to throw away so I claimed it. It costs about 40 cents a foot if you can find it. Once I get the pick guard folded back I simply need to add the caps which should only take a few minutes but its worth a before and after photo for someone wanting to make those changes. I never found the stock wiring for a Strat all that useful. Granted, if the bridge pickup is super shrill it might warrant its own tone pot but with the kinds of balanced pickup sets being sold now that's become more of the exception these days instead of the rule. I rarely if ever use a tone pot except maybe when the strings are new and a bit bright. I can use a global tone control for that and use the extra pot for something else. I might want to make one a treble pot and one a bass pot. Using both evenly can give you that Clapton woman tone. Getting the second pot to roll off bass comes down to using caps as a high pass filter series with the signal. Caps pass AC Voltage. Instead of passing the high frequencies to ground you use the cap to only pass highs to the output jack. With the right values selected the bass wont pass but the treble and mids will. This makes it a bass pot. Full up, it passes all frequencies, full down it removes all lows and enhances the quack tones Strat pickups produce. Using those .033uf caps will remove treble leaving the midrange. Using both pots will leave nothing but midrange, thus the woman's tone plus all kinds of variations based on how much you dial up and the pickups selected. I have one other Strat with this plus I removed the 5 way switch and installed 3 toggles which are also forward reverse phase switches. The tonal combinations I can get are excellent.
  6. I did get that new bridge in but I haven't taken any photos since I put it on. To be honest, it didn't make that big of a difference because I essentially have the bridge set the same way as I had the classic style set. I did discover something interesting in the process however. Angling the barrels didn't have the same effect as adjusting separate saddles. Example, you would think if you turned the E/B saddle counter clockwise, the E string would increase in pitch at the 12th and the B string decrease. That theory is less predictable because the string angle is very steep coming off the saddles with a string through body design. Lengthening or shorting the strings changes string tension therefore countering the string length by changing the amount of relief the neck has. Turning the saddle clockwise increased the second strings tension and the intonation went up instead of down. Pretty crazy actually because its actually the opposite of everything you're told. The other thing is the angled barrel isn't good for tone or tuning. I got allot more string buzz too. I suspect its because the breakaway point on the string gets longer. With the barrel at a right angle to the string the breakaway is sharp and affects the strings vibrating in either direction and the string tone is pure. When you angle the barrel the vibrating string hits the barrel sooner on one side then the other and there is more string buzz at the barrels. I did the test multiple times using highly accurate measurements to rule out all other possibilities and my conclusions remain the same. Angles barrels are not a good method of intonating strings. maybe if the saddles came to a point like an acoustic bridge does so there isn't large area for string contact it would work. many saddles are angled and have no problems because the contact point is very narrow. Large wide barrels are more like a Buzz bridge for sitar tones as you turn them sideways. At least for the string gauges 9/46 I use. I used a micrometer to set the barrels at a perfect 90 degree angle to the frets. From there I could tweak the intonation and it sounds great for chords or leads. One other item I used which was one of those Dial type string measurement tools. Normally I'd set the first string height to 3/64ths and the 6th to 5/64ths using a ruler then use an under string radius gauge to set the rest of the strings which gets the action about as good as you'll ever need it. Instead I used this. These will measure string height down to 1/1000 of an inch or even half that much. These are normally used for setting nut height but I found that can be used for string height at the 12th as well. I set the strings from High to low at 35/1000, 40/1000, 45/1000, 50/1000, 55/1000, 60/1000, 65/1000 I get no string buzz, strings bend really nice, I don't get fatigue playing chords and the intonation is excellent. Not much more I can ask for. I do question the accuracy of this ruler however. I bought 2 of these, 2 different types on EBay and neither seem to measure the correct height 60/1000 on the ruler is closer to 50/1000 on the dial type meter. I don't think they stenciled those generic rulers very well plus looking under a string can create a shadow making the accuracy tougher to read. In any case I got better results using the dial type in this case and I can play now without sour notes or buzz where those were an issue before getting things set right.
  7. Bit by bit I been getting this tele up to my performance standards. This week I did some more tweaking to the electronics. I didn't buy the best pots out there and though they work fine, they tend to get a little dark rolling off those new alnico pickups I installed 2 weeks ago. I also wired the to pots differently then a normal tele that has a master volume and tone. I instead wired the two pots as separate volume controls for each pickup which I prefer, especially for recording because I can get changes to the pickup levels without having to adjust their height. Even there it was only good when adjusting one pot lower by 1 or 2 numbers. any more it had little effect> I picked up a bag of 25 .001uf bleeder caps for $2 I also bought another 10 .033Uf tone caps for $1. I figured I'd restock my parts cab. The trick to buying them low cost is to search by value, not by what you want to use them for. When I first googled Bleeder caps I was seeing single caps for $5 plus $2 shipping. Quite a price gouge if you don't know how to search. I found them in bulk for much less with free shipping. I really like what they do when turning the volume down now. The caps are actually quite mild. I could probably double or triple them and still not need a resistor in parallel. I'll probably keep it as is though. I have a nice range of mix using one pot only and when I turn them both down a bit then blend they have another range of blends which are even cleaner sounding. It essentially doubles the tonal range I had before which is exactly what I needed. I'll likely put a .033 and a bleeder in the Strat I built. The cap I have in there is too mild and barely makes any difference. I'll have the bleeder connected to a pot so I can either dial it in or out completely as the volume is used. I like both options on a Strat. sometime I like them to darken depending on the drive pedal used, other times I like it to brighten and get a classic Strat Funky clean sound when turned down.
  8. I been dealing with surge protectors for at least 40 years now. I work in the business equipment industry and we include one with every piece of equipment we sell. ESP, The manufacturer guarantees repairs on any piece of gear damaged by a voltage surge. So far we've only been able to collect on a couple of them and even there we couldn't be sure if the damage was caused by an actual surge or defective surge protector which simply failed. What you don't know is how many times that unit actually did its job and protected the gear. Most do not have any kind of logic to tell you how many times its protected, but we do have new style units that actually have that and are sold with units costing over 100K now. Given the fact most business equipment is networked these days its important their power source isn't loaded with voltage spikes which can cause data and reboot problems when there is voltage problems, especially in a city like Houston which is noted as being the most air conditioned city in the US. Between all those AC units and violent tropical storm systems we see here, it put allot of stress on the AC grid and the surge protectors seem to arrest the spikes that can do the most damage. To the OP. What power conditioners cannot do is prevent the loss of power. They can prevent large spikes in voltage but only a UPS/battery backup or a backup generator can prevent low voltage/brownout conditions. If the voltage sags, it sags. nothing you can do about it. If the conditioner is any good it only protects against voltage spikes and noise as SteinbergerHack mentioned. For most tube amps they don't do jack squat for you, in fact they might introduce more noise then they remove if its a conditioner designed for computers. Your power transformer in a tube amp does far more to separate your gear from the AC supply. Its primary coil is separate from the secondary coils and only mirrors what the primary coil sees using inductive transference. The secondary is then converted to DC where there is plenty of capacitance to smooth any spikes that may make it past the transformer. AC voltage would need to be a good 20V lower before much of a difference in tone might be heard with most tube amps. The exception might be when the amp is a hybrid and has SS components that have narrow voltage parameters. Having played enough clubs to know what you're dealing with your issues may be related to beat up outlets with damaged grounds. Last club I played that had stage outlets, most of those outlets were so beat up you could barely get a connection and if you did they were so loose the music could vibrate the plug right out of the wall. The bass player in my band is a licensed electrician with full certifications. When we play a club that has bad/questionable outlets he brings an electrical snake that connects directly to the breaker box. We also use 20 amp isolation transformers which takes us off line and prevents ground loop issues too. Given the OP's description I think the cause of his issue probably doesn't have anything to do with the power. Its more likely a defective tubes. If you didn't buy the tubes yourself you have no way of knowing whether they stuck used tubes in that amp either. Its not like tubes have a meter on them to tell you how many hours they've burned. Even buying them from reputable dealers is no guarantee you couldn't have gotten some defective tubes. Last time I bought tubes for my Blackface I had to send the first 2 sets back for being defective. I bought Ruby tubes first which means they were shipped from china to Ruby half way around the world, where they unboxed and powered each one for matching them. Matching doesn't test the audio quality, it simply measures current rating for biasing. After that they reship them to customers so the elements have seen allot of vibration and banging around being shipped. The first set started arching out with large popping within 30 seconds of power up. They went back immediately. Second set were JJ's and had the same kinds of issues. Noise in the background when simply idling. I learned a long time ago tubes don't get better as the burn in. They only get worse. The third set were Electro Harmonix and were as good as another set I bought for another amp. The JJ preamp tubes were awful too. Low output, Midrange tones and distorted easily. I switched to JJ's and it was like day and night. Bright, clean, low noise and low distortion. Makes a Fender amp sound Like I was using RCA tubes in it again. I had good luck with Groove tubes too. Got nearly 20 years out of that set. Fender owns them now which is a good move for them. The tubes are sold with three different power levels so you can choose clean, driven of in between depending on the amp you have. My advice. if the amp sounds bad at home, I doubt the power at that gig had anything to do with it. You may have moved the amp before the tubes had time to cool off and damaged its filaments when knocking the amp around. The other possibility is the load was incorrect for the head. An impedance too high will burn your power tubes up very quickly and the fidelity can go right down the tubes. (Pun Intended) In other cases you can even damage or blow the screen resistors. Check and make sure make sure the power tubes don't glow cherry red. If they have a blue tint you're probably OK. If you have an extra preamp tube try swapping them one at a time and see if you can isolate the bad one.
  9. I just saw a concert on TV over the weekend that had the Cure playing. They had a line of small amps they were using. Looks like they were Rolland Cube amps. They turned the B in CUBE to an R using a black piece of tape) By the size they couldn't have had more then a 12" in each one, Maybe even 10's. That outdoor audience must have been 100,000 people or more. In an article they said their stage volume has always been based on an acoustic drummers drum set.
  10. You could simply get one of these and get what you need. Its got a built in EQ that lets you shape the tone and its got Overdrive or distortion so you don't need 3 pedals to do what one can. you can find these used on eBay for less then $50 too. Very well made, all metal knobs and cases, and they are true bypass. The first knob is overdrive and distortion. Second is drive and volume, third are treble and bass, the forth is called contour but its essentially a midrange that can be added of subtracted or shifted in frequency so you can get just about anything you need. What I like about the Marshall pedals is the preamp and tone give you a string touch which is identical to their amps which means you can play fast and with a light touch without getting bogged down in tone suck as many pedals do. Bypassing removes it from the chain completely since its true bypass.
  11. You must be using something like a Boss Noise suppressor if that have that configuration. You'd normally use it by connecting the drive pedals in its loop and the pedal was connected where you would normally have the drive pedals in the chain. I used to use one of those for about 6 months then dumped using it. I didn't like what it did to the sound when using certain pedals. You want to be sure you use that pedal on its own power supply. If you put it on a daisy chain with other pedals some weird audio artifacts can occur which sound like distortion. (which might be the reason you posted this thread) It took me awhile to figure out what was causing it. I'd get this grainy sound like a blown transistor when sharing power with other pedals. When I used it on a separate Boss wall wart it cleaned right up and those problems disappeared. It still seems to lower the signal level however. When I removed it from the board and simply used the drive pedals bypass I got allot of gain and tone back. I thought about trying a Hush pedal instead but eventually built a dual loop pedal instead. I now have two loops with two drive pedals on each and I can set up any configs I need and simply bypass either or all with the two switches and completely remove those pedals and their wiring from the pedal chain. You don't realize how much tone and gain suck you have until you shorten your effects chain. Even if the pedals are true bypass, there's allot of extra wiring there that reduces the signal. My suggestion is first try a separate wall wart for that particular pedal. Either a Boss or a Dan Electro Zero hum work properly. if you still have issues try a different gate pedal.
  12. The limitations are going to be based on the components that comprise the circuits and their power consumption. Theory vs reality are two different things. Tubes especially are limited to the components and tubes readily available. They aren't designing new audio tubes any more so you're stuck with what's available for building amps which is pairs of tubes which produce maybe 120W total. I've seen 200W guitar amps and 300W bass amps but anything larger really isn't practical cost wise or in actual use. You could spend a half a billion dollars designing and tooling a new factory to manufacturer a new type of tube and there is no guarantee it would sound any better then what's already available. You could spend tens of thousands making all the support components as well and build an amp nobody wants to buy too. Whey spend all kinds of money designing a single 400W tube amp when you can simply buy 4 X 100W amps? Its much cheaper to simply buy several smaller amps and a hell of a lot easier to move them too. Or you can do like most guitarists. Get one great sounding amp and simply mic it. There was a time when manufacturers were in competition building high wattage stage amps. I still have a Sunn Concert lead head from 1967 which is 200W. I don't play many places where I can actually use i6t however. I used it as a bass head driving mid speakers mostly. The trend for big amp designs pretty much ended with the rise of much larger sound systems capable of micing an entire band. When I was a kid something like a Vocal Master, Kustom, Vox etc PA was pretty common for most working bands. Most weren't much more then 100 to 200W tops and were only used for vocals. Musicians could easily get by with 30W amps that matched the loudness of a drummer. Even the Who during the 60's which were noted as being one of the loudest bands ever only used Vox or Marshall PA's which weren't more then 4X12 speaker columns with 200w heads. They typically offered additional power amps to run more cabs. They would use those PA's often without any instrument mics or stage monitors and simply used louder instrument amps for big shows. Late 60's early 70's you saw some of the really big systems being used at shows like Montgomery Pop and Woodstock. By the mid 70's just about any band you saw playing a large venue had huge systems. I saw at least two dozen shows at the Phili Spectrum PA's this size was pretty normal. It wouldn't matter what size amp you use on stage. If its miced people will hear it. if it isn't, they wont. Many metal bands and headliners still use some big stage amps but much of that is for show. Since about 2000 the trend on amp size has been getting smaller. Speakers are more efficient so you can use smaller cabs and be just as loud as the old ones. Why pack a 4X12 marshal cab with 25W speakers and use 4 cabs when you can pack one cab with 4 X100W speakers and actually be much louder due to them being twice as efficient. Hauling less gear means fewer roadies to move it and that means you get to keep more of the money you earn instead of paying hired help. There were musicians even back in the 70's who found some of the smaller tube amps could produce some really great tones. So long as they miced them up it was no problem. If you need to play louder, simply bring more PA gear and mic the amp. If you cant afford the gear hire a sound company to do all that work. You can show up at a gig with everything you need in two hands. You can take all that energy you waste moving big amps and put it into the music instead which in turn gives the audience a better show. Dogging huge amps at 3 in into a truck sucks big time. Try it for a few years and you'll learn soon enough. When you haul big amps you typically have to unload all that crap when you get home too so nobody breaks into the truck and steals it. If you can put it all in the trunk, nobody's going to even know its there and you can always get it out in the morning.
  13. Pots don't have a great effect on tone. What happens when you put a 500K in place of a 250/300K pot is the sweep changes. Instead of the volume tapering down at an equal amount it will do practically nothing until you get to maybe 2 or 3 then it cuts off all at once. The taper is wrong for single coil pickups unless you buy a special taper that quickly attenuates towards the high side. What you actually want to brighten thing up are bleeder caps. I bought some .001uf caps myself yesterday because I had run out. Cost me a whopping $3 for 25 of them and I ordered 25 .033uf tone caps for 2 from the same vendor for $2. You have the option of connecting the cap by itself or using an additional 150 ohm resistor in parallel with it depending on the type or pot, pickup and the amount of tone you want the guitar to retain. You can find the combination ready to install for a buck or two like this and you simply solder it to the center and hot leg of the volume pot (not the grounded leg) This will make the tone much brighter as soon as you dial the volume down a little. It will not affect it at full volume. The only fix for full volume tone is to get pickups with brighter tone. Or you could add active electronics and add an on board EQ circuit. Artec makes some excellent circuits for this. The batteries last for years without needing replacement which is good because you typically have to Velcro the battery in the cavity under the pickguard. I have a couple of guitars with this arrangement and it works quite well. Personally I prefer to simply choose pickups that already have the ideal tone and then I only have to worry about balancing their output with pickup height. There is one other item you could try. I'm not 100% sure how well it might work because I don't use those single coil humbuckers. You could wire the two single coils in series for impedance closer to a PAF then try using a 500K pot. Switching them off and on as singles might be tougher with a blade switch, and you'd still have the taper issue when running them singly but in the 2 and 4 positions you might be OK. It will make the pickups louder in those positions but you'll find loudness is the least of your worries when you have amps and pedals that can remove paint from the walls. I learned a long time ago I prefer vintage would pickups over all these pickups claiming they are hot wound. A strat pickup sounds its best when wound at 5.6 to 6.2K ohms. Anything above that's going to kill the highs and produce mud tones. Seymour winds their mini HB at about 9.8K they typically change the magnet strength so it will work with other single coil's and blend ok. Dimarzio is crazy high at 13.8K. Even with a weaker alnico magnet its unlikely to blend with a vintage single coil very well. You have to be careful with the generics because they don't know how to balance the impedance properly and all they do is wind as much wire as they can on the bobbin as though more is better. It isn't, its in fact the worst thing you can do for good tone as you are finding out. I'm not a huge fan of humbuckers in Strat's to begin with. I have one with an ideally matched full sized HB in the bridge position. It took a lot of experimentation to find that one and it wound up being the same type of Mighty Mite pickup EVH used. I've also tried a Strat with P90's and Gibson style Mini Humbuckers. Neither were worth the effort in my book. Nothing but mud tones and 3 of each was overkill. They didn't provide much difference in tone and you couldn't hear much change in any of the PO positions. One last option you can use to add treble is to take a .047uf cap and wire it to a pot so the cap is in series with the pickups. This lakes it work the opposite from a normal tone control that has the cap in parallel with pickups. As you turn the pot down, it removes bass from the output instead of cutting treble. The cap value simply have to be higher to pass most of the frequency and only removes the bass tones. Rickenbacker used this trick on many of their bridge pickups on guitars and basses. Danelectro also used a similar filter combined with tone so the pot would remove treble turned in one direction and removed bass turned the opposite direction. Again, I prefer to get my tone by choosing the right pickup first. The rest is just optional control. Try the bleeder first. you may have to turn the volume down a tad for it to work but it usually does the job on most Fenders and it is a stock option of most Tele guitars because their bridge pickup is usually wound much hotter and needs the bleeder when truning down to prevent muted tones.
  14. tubes don't produce voltage and current. that comes from your wall outlet and is stepped up and down at different levels by the power transformer to whatever the tubes need to operate. You typically have heater voltages and B+ which is the high voltages most tubes use to actually amplify. You should also know its not voltage that kills, its the current that does that. You can easily generate 20,000 volts simply combing your hair but other then a small jolt when you touch something grounded its not going to kill you because the current is so low. Where current is most dangerous is when the body acts as a ground and the current passes over the heart. Example, touching a high voltage contact with one finger while the rest of the hand is touching the chassis will allow the current to pass from one finger to the hand before t gets to ground. It will hurt like an SOB but unlikely to stop your heart unless its weak and the surprise is enough to give you an attack. On the other hand, if you touch a contact and the second hand is or bare foot is touching ground, then you set up a path that allows the current to pass over the heart (like those two paddles they use in and emergency room for heart attacks) First thing you're taught as an electronic tech is to always work on an amp with one hand only when testing. The second hand goes in a pocket or behind your back. This prevents a path across your heart. You don't want to lean up against a grounded work bench either. I know a guy who did that when testing a TV fly back transformer ang got zapped in his crotch with 10,000 volts. It was as painful as being kicked between the legs. Lastly, tubes aren't set with voltages. B+ voltages are fixed to whatever the tubes are designed to run on. Biasing tubes us done by balancing current levels which is actually very low in most tube amps. 20~30 milliamps is pretty common in most power tubes. Unless you're changing the power tubes and know the proper procedure for setting the bias you have no reason to be inside the amp. That's what they put a sticker on there that says, " To be serviced by qualified personnel only. No user replicable parts inside" That translates to, anyone who didn't go to college and get an electronics degree doesn't know jack from shinola so stay the hell out and leave the repair work to professionals who do.
  15. Is this the head? If so this is a mono head. There is no biamping of any kind. As you can see on the back it says speaker outs with a single box saying 4 ohm minimum. There is nothing there to indicate it has a stereo or dual power amp output. The DI output is NOT a speaker output. Its a line level output for recording of connecting it to a mixer or the input of another power amp. If you're trying to connect that to the speaker youd be shorting the head out. I'm surprised you didn't blow the amp up completely. Whenever you're in doubt about things like this you should always download the manual and read it before you start messing. You may actually save yourself from blowing the amp up. These kinds of miniature class D bass amps pack allot of power for their size but they are incredibly complex. Your average amp techs are often clueless on how they work no less know how to repair them. Once they blow its cheaper to buy a new one then it is to repair one. I have one of those Ampeg Portaflex class D heads. I try not to run it past half power. When run hard they overheat and shut down till they cool off. If you have one of the older Mark Bass heads like the Mark 8 it does have a crossover EQ and line outputs which let you drive a second amp. The ones I saw did not have two built in power amps so its not much different then the amp above besides having extra line outputs which are connected to an EQ/crossover circuit. With those heads, your set the built in amp to produce bass tones then whatever power amp and speaker you connect to the outputs you can set for mids and highs. The connectors on the front are line level outputs NOT speaker outputs. If you connect them to a speaker its like putting an 8 ohm resistor over the preamp output.. You virtually short out the preamp when you do that and feeding a speaker signal back into the preamp creates a feedback loop. Very, Very bad. You need an additional power amp and speaker cab to use the crossover. If you had two of these amps, one with say 15" speaker cab and another with 10's and a horn, you could then use the high output to feed the power amp input on the second amp which bypasses its preamp. The one head is then the master and the second is the slave. This way one set of controls runs both heads and you can adjust the tone of the second amp with the crossover frequency and balance the level with the balance knob. This one also has a stereo chorus output which can feed another amp. looks like the extra output is high frequency so you could either drive a guitar amp or PA mixer direct if you wanted. you just have to be careful with the levels not to overdrive the second amp. If you know specifically which mark head it is I can get you more specific details. There should be manuals on any of these even though they are old, someone likely posted them. if not most of it is the same with most amps and pretty easy to figure out Peavey does make some pro gear that has dual power amps for bi-amping, but I don't thing the old blackface do. Tahy may have made a separate power amp as an accessory but I've never seen a dual power amp in the old ones. My buddy has an equipment endorsement with peavey so I get to see allot of their top end gear. He uses one of their bass heads that has two power amps built in. He has his cab wired for it where one power amp drives a15" woofer and the other drives 2X10's and a horn. When both outputs are used the crossover separates the frequencies, and drives the lows to the 15 and highs to the others using separate power amps. When only the one speaker jack connected, both power amps drive the same cab full frequency and the crossover is disconnected. Like I said, that's a very expensive pro model that's about 1200 watts and very expensive. Those old blackface are maybe 250W mono heads.
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