Members wagdog Posted January 3, 2009 Author Members Share Posted January 3, 2009 Yeah man, if the clean channel + pedal is where it's working for you, then I wouldn't mess with it! If you take out the relays like I did, there really is no going back. Steve A seems to think it would work fine with the relays in place. I agree with him, but I think the clean "channel" would need some work afterwards. Just didn't seem worth it to me as I never used the clean channel anyway. Link to comment Share on other sites More sharing options...
Members ZombieCat Posted January 3, 2009 Members Share Posted January 3, 2009 Yeah man, if the clean channel + pedal is where it's working for you, then I wouldn't mess with it! I hear ya. I think my best bet right now is to replace the crappy speakers that are in the Crate 212 cab then decide where to go next. I am going to go re-read the V33 mod thread as I remember some people listing some speakers they are using. Link to comment Share on other sites More sharing options...
Members jdpkeeper Posted January 3, 2009 Members Share Posted January 3, 2009 I hear ya. I think my best bet right now is to replace the crappy speakers that are in the Crate 212 cab then decide where to go next. I am going to go re-read the V33 mod thread as I remember some people listing some speakers they are using. i'd like to hear what you decide on, as im on the fence about replacing the stock 212 crate speakers, just not sure what i would go with at this point. Link to comment Share on other sites More sharing options...
Members wagdog Posted January 3, 2009 Author Members Share Posted January 3, 2009 I have to replace the stock speakers in my v18 2x12, they are truly {censored}ty. Link to comment Share on other sites More sharing options...
Members ZombieCat Posted January 4, 2009 Members Share Posted January 4, 2009 I think I am going to go with the Green Beret from Speaker Warehouse which are Celestion Greenback clones. I have read some good things about these and the price ($65 each) is pretty good. I need to do some more research on them before making the final call. Link to comment Share on other sites More sharing options...
Members wagdog Posted January 4, 2009 Author Members Share Posted January 4, 2009 Please let me know when you finally do replace your speakers. I've got a couple other more pressing things to spend money on right now, but I DO want to get those speakers replaced. Link to comment Share on other sites More sharing options...
Members ZombieCat Posted January 4, 2009 Members Share Posted January 4, 2009 I decided to order the Green Beret this morning. Being I am in California and they are in Kentucky, if I am lucky I will have them on Friday. I will try and get some good before and after clips so everyone can hear how they sound. Link to comment Share on other sites More sharing options...
Members ZombieCat Posted January 13, 2009 Members Share Posted January 13, 2009 Speakers came Friday and I have them already swapped in. Since this is not really related to the SLO mods I posted my thoughts in the V33H mod thread. In essence, I really like the green berets. http://acapella.harmony-central.com/showthread.php?p=32206521#post32206521 Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 15, 2009 Members Share Posted January 15, 2009 Mr. Dog: After having my Soldano-ized V18 blown away at the last high volume blues jam, I decided it was time to do the "dirty deed" to my V33H. I drew it up and got out my crayons for a color-coded layout drawing for those artists out there who majored in "Paint By Numbers"... I couldn't find my tin snips so I decided to leave the relays in place- the Clean channel should offer me something different for rhythm guitar, even if will not sound as pristine as the stock V33 clean channel. And that seems to involve less work than removing the relay and adding jumpers. (BTW I ohmed out the relay and with it not energized it is in the OD mode.) For now I am skipping all of the mods I have been doing to the output section. Like replacing the 470k grid loads for the EL84's with 220k resistors. Most EL84 amps use the 220k grid loads (aka bias splitters for a fixed bias amp) because they can sound really ugly if your signal level is too hot. But it just occurred to me that the IC stage immediately before the phase inverter will limit the signal that eventually reaches the EL84's because it is powered by a +/- 14.7vdc supply so maybe the 470k resistors are not a problem... Steve Ahola www.blueguitar.org P.S. It had been suggested to add a switch for the .001uF bright cap since it was typically needed with humbuckers but not single coil pickups so I figured out how to wire that up, too. The big test will be on Saturday when I will find out if I get blown out by the big dogs again. The schematic is screwed up in its depiction of the Relay 2C contacts: in the Normally Open (i.e. Clean) position it grounds the junction of R8 and R11 (which are not routed through the relay as shown). And the Relay 1B contacts do not connect to Relay 2C as shown (the signal coming from the Clean volume control wiper is not grounded in the Normally Closed OD position). I will draw up a corrected schematic and get it posted. Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 15, 2009 Members Share Posted January 15, 2009 Well having a clean channel would be just great to have for me, I love the portability and power of the V18. Now that I have another V18-112 coming in I can get started on the D*mble ODS 18 mod which uses a 6vdc coil DPDT relay to switch between the two channels. I have the basic drawings posted over at ppwatt.com but at this point they show a DPDT switch and not the relay. http://www.ppwatt.com/node/16157 You can join ppwatt.com and ask me questions about it over there rather than have us crap all over Wagdog's thread here... Steve Ahola Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 15, 2009 Members Share Posted January 15, 2009 I agree Mouser's site is very easy to use and they always seem to ship pretty fast. I am getting a bit wishy washy on doing this. I was thinking about it some more last night and I am wondering what this mod will sound like with my Big Muff. Right now, even with almost no gain, the OD channel sounds like crap when I use the BM but the clean channel sounds just brilliant. EDIT: I literally just got the Big Muff last night so that is why I am now having second thoughts after using it. Mr. Cat: With the Soldano conversion, the Clean channel is *almost* stock except for V2A. The first stage of V2 uses a 39k cathode resistor which creates the assymetrical distortion which is one of the characteristics of the SLO design. It also bypasses the 100k plate resistor with a 0.001uF cap which bleeds off some of the highs. You could add a switch to the amp to toggle the cathode resistor from 39k to the stock value of 10k, which would clean up the Clean channel a lot. If I can ever figure out the relay switching circuit on this amp it would even be possible to add a 3rd relay which would change the cathode resistor and possibly even remove the 0.001uF cap across the plate resistor as you switch channels (the second item could cause some switching noises). Steve Ahola P.S. I've been using my Clean Channel modded V18 for pedals because it is so neutral and allows the sound of the pedal to come through. So I think I understand your feelings about your new Big Muff... Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 22, 2009 Members Share Posted January 22, 2009 I corrected some problems and made some revisions to the Soldano Conversion for my V33H (thanks to everybody's suggestions on this design here and over at ppwatt.com and The Gear Page!) The amp now has 3 channels- just like a real SLO. Well, the Crunch channel is really just a special mode of the Clean channel (just like the real SLO). I thought that the Clean channel was much softer than the OD channel so I made a few changes. R7 dumps a lot of signal to ground; you can consider R5 & R7 to be a 470k/470k voltage divider which feeds the RC network of R6 & C2. So I increased the value of R7 to 1M. I also did the same with R11- the grid stopper/grid load (!) for V2A increasing the value from 470k to 1M. (In OD mode it is grid stopper and in Clean mode it is grid load). To keep the RC filter value the same I guess that you could replace C7 with a 0.01uF cap but I left it with the stock value of 0.02uF. To increase the gain of both channels I decided to replace R14 with a 220k resistor, which corresponds more closely to the value in the SLO schematic. I also reverted the EL84 grid loads R71 and R98 back to 470k from 220k to restore the full volume back to the amp. I experimented with a 470k/470pF RC network of R6 and C2- it made for a more crunchier and thicker sound. I did miss the cleaner sounds of the stock R6/C2 network so I wired up a full sized DPDT toggle switch about halfway between the input jack and the cabinet. Adding a 560k resistor in parallel to 2M2 brings it down to around 470k and adding a 430pF cap in parallel with 50pf brings it up to 480pF. For the phase inverter I really like having a 1k2 resistor in the cathode (R28) and a 47k resistor on the tail (R31), especially when there is no negative feedback loop. These are the classic values used in the Vox AC30, which I believe is one factor that contributes to their chiminess. For allout crunch you might put a 820 ohm resistor on the cathode and a 10k resistor on the tail. Or just leave it stock for now. R36 and R76 comprise my "quick'n'dirty" reverb fix for the V33. The rest of the values are from the Soldano SLO schematic. A few notes: all of the preamp tube cathodes (except V2a) have a 1k8 resistor bypassed with a 1uF cap (rated at 25+ vdc). Note: be sure that the positive terminal on electrolytics goes towards the tube cathode. All of the preamp plate resistors (except for V1a) are 100k. The V2a plate resistor is bypassed with a 0.001uF/630v capacitor; solder the capacitor leads to the resistor and then insert the resistor leads into the pcb. For jumpers, etc., I have introduced a new nomenclature on the drawing here. Most of the capacitors and resistors are located either horizontally or vertically. So I am going to call the copper pad which is closest to the left or bottom edge of the PCB (viewed with the pots facing you) "A" and the copper pad which is closer to the right or top edge of the PCB "B". In the event that the component was running diagonally we would give preference to the left-right axis. For an example, the 0.001uF bright cap would be added from C5 terminal B to R77 terminal A, or C5b to R77a to simplify things. Actually in this particular case there are two linked terminals on the right side of C5 so it would be more correct to refer to the pad as being C5b2. As long as you are just replacing a component with another component or a jumper, there is no need for this new nomenclature. However, if you are adding a jumper or component from one pad to a completely different pad it will it easier to follow the text instructions. Steve Ahola P.S. Here is a link to the drawing at my own site: http://www.blueguitar.org/new/schem/misc_mod/crate_v33_soldano_conversion-layout.jpg P.P.S. BTW this amp really rocks! I would go so far as to say that it is the best amp I've ever played. And it is probably the easiest conversion to follow of all of the ones that I have drawn up. If you were to have an amp tech do the mods for you I think that it would take around 2.5 hours. I am using Groove Tubes for the preamp tubes: 5751M for V1 & V2, 12AX7M for V3 (the PI). And just the stock Sovtek EL84's that came with the amp. I was hoping to get some song samples recorded at a jam tonight but it was raining and getting late so I had to skip that. I got to play through a 50 watt Aiken Invader but the whole time I was thinking that I wished I was playing my V33H! Link to comment Share on other sites More sharing options...
Members wagdog Posted January 22, 2009 Author Members Share Posted January 22, 2009 This is awesome Steve. I'm going to post a note in my original post so people interested can see that they can keep their clean channel. For me personally, it's not a big deal as I'm a 1 channel kinda player, but I can see where it would be useful. Link to comment Share on other sites More sharing options...
Members ZombieCat Posted January 22, 2009 Members Share Posted January 22, 2009 Steve your knowledge of electronics is impressive! While I am no longer planning on doing this mod, I have been following this thread just because it is cool. I was really interested to read this part. I also reverted the EL84 grid loads R71 and R98 back to 470k from 220k to restore the full volume back to the amp. Now can I take this to mean, I could build a simple switching circuit that would swap these resistor values and give me a way to cut down on some of the amp's volume so my neighbors will love me again? This is also with the assumption I have not done any mods to the power amp section at all. I am seeing this as a switch on the back panel to toggle the different resistors that of course would ONLY be used when the amp was off. Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 23, 2009 Members Share Posted January 23, 2009 ... Now can I take this to mean, I could build a simple switching circuit that would swap these resistor values and give me a way to cut down on some of the amp's volume so my neighbors will love me again? This is also with the assumption I have not done any mods to the power amp section at all. I am seeing this as a switch on the back panel to toggle the different resistors that of course would ONLY be used when the amp was off. You can replace the two grid load resistors with a dual ganged pot, which Ken Fischer considered to be the most accurate post PI master volume circuit (his Type 2) since when set to 10 it is essentially out of the circuit. It also does not require the two extra coupling caps for the more post PI master volume circuit, which he calls the Type 1: http://www.blueguitar.org/new/schem/trainwreck/trainwreck_mv_type_2.gif Although the drawing shows a dual 100k pot (really slick for bluesy sounds from a BF/SF Fender-ish amp) for the Crate V18 and V33/50 you would want to use a dual 500k pot (so that you have full volume when set to 10). BTW I had replaced the 470k resistors with 220k resistors because it can keep the EL84's from going "into the red" and getting an ugly sound when the voltage on the grids exceeds 14 volts. But I later realized that the pre PI buffer limits the signal going into the PI to around 25v P-to-P so these Crate amps can get away with the 470k grid loads (I don't think that anybody complains about these amps having a harsh sound when pushed hard- it is usually that the amp is too muddy). Steve Ahola Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 23, 2009 Members Share Posted January 23, 2009 This is awesome Steve. I'm going to post a note in my original post so people interested can see that they can keep their clean channel. For me personally, it's not a big deal as I'm a 1 channel kinda player, but I can see where it would be useful. FWIW the Clean and Crunch channels/modes do give you access to sounds that you don't get from the OD channel, probably because you have one less gain stage. And it also gives you more control over your volumes, in case you want a clean sound that is louder than your distorted sound (within limits- clean and crunch do not get as loud as OD). BTW I left off the Bright switch because I think that the Presence switch should cover that (when switching from humbuckers to single coils). It isn't a real Presence circuit like a tweed bassman or Marshall, but just a treble bleed circuit right after the Treble pot. But as you say the single channel as in the modded V18 works just fine- I played a gig Sunday night with my Soldano-ized V-18 and brought along some pedals "just in case" but I didn't need them at all so I unplugged them after the first set. I have never had so much fun playing an amp which was so responsive to my playing, and to the settings of the controls on the guitar (a PRS SE Singlecut w/ a BurstBucker 2 in the neck and a BurstBucker Pro in the bridge- a guitar that smokes my Gibson Les Pauls...) Steve Link to comment Share on other sites More sharing options...
Members NotDead Posted January 23, 2009 Members Share Posted January 23, 2009 I asked if it was possible to add a switch to the V18 circuit to add a gain cut from V1 to make the same kind of "clean channel" as the V33.Anybody gonna pipe in? Link to comment Share on other sites More sharing options...
Members sssteeve Posted January 23, 2009 Members Share Posted January 23, 2009 I asked if it was possible to add a switch to the V18 circuit to add a gain cut from V1 to make the same kind of "clean channel" as the V33.Anybody gonna pipe in? Well, that was my very first V18 conversion project last October: to replicate the Clean channel of the V33 in my first V-18 (they have grown and multiplied- there are 5 of them now!) It required removing a lot of parts and adding jumpers so there is no way that a simple switch could toggle it back to the stock V-18. Here is are links to the drawing and to the schematic to give you some idea what is involved: http://www.blueguitar.org/new/schem/misc_mod/crate_v18_clean_channel_conversion_layout-preliminary.jpg http://www.blueguitar.org/new/schem/misc_mod/crate_v18_clean_channel_conversion-preamp_schematic.jpg I am probably going to add the same Clean/Crunch switch circuit that I used in my Soldano-ized V33. And I was planning on making some further revisions to the circuit. Good luck! Steve Ahola Link to comment Share on other sites More sharing options...
Members ZombieCat Posted January 23, 2009 Members Share Posted January 23, 2009 You can replace the two grid load resistors with a dual ganged pot, which Ken Fischer considered to be the most accurate post PI master volume circuit (his Type 2) since when set to 10 it is essentially out of the circuit. It also does not require the two extra coupling caps for the more post PI master volume circuit, which he calls the Type 1:http://www.blueguitar.org/new/schem/trainwreck/trainwreck_mv_type_2.gifAlthough the drawing shows a dual 100k pot (really slick for bluesy sounds from a BF/SF Fender-ish amp) for the Crate V18 and V33/50 you would want to use a dual 500k pot (so that you have full volume when set to 10).BTW I had replaced the 470k resistors with 220k resistors because it can keep the EL84's from going "into the red" and getting an ugly sound when the voltage on the grids exceeds 14 volts. But I later realized that the pre PI buffer limits the signal going into the PI to around 25v P-to-P so these Crate amps can get away with the 470k grid loads (I don't think that anybody complains about these amps having a harsh sound when pushed hard- it is usually that the amp is too muddy).Steve Ahola What an elegant solution using the dual ganged pots. I never would have thought of that. This is going to be my next mod for sure. Link to comment Share on other sites More sharing options...
Members shooto Posted January 23, 2009 Members Share Posted January 23, 2009 could you post the sound clip again? Link to comment Share on other sites More sharing options...
Members NotDead Posted January 24, 2009 Members Share Posted January 24, 2009 Well, that was my very first V18 conversion project last October: to replicate the Clean channel of the V33 in my first V-18 (they have grown and multiplied- there are 5 of them now!) It required removing a lot of parts and adding jumpers so there is no way that a simple switch could toggle it back to the stock V-18. Here is are links to the drawing and to the schematic to give you some idea what is involved:http://www.blueguitar.org/new/schem/misc_mod/crate_v18_clean_channel_conversion_layout-preliminary.jpghttp://www.blueguitar.org/new/schem/misc_mod/crate_v18_clean_channel_conversion-preamp_schematic.jpgI am probably going to add the same Clean/Crunch switch circuit that I used in my Soldano-ized V33. And I was planning on making some further revisions to the circuit.Good luck!Steve Ahola Well I wasn't expecting a full conversion back to stock at the flick of a switch, but could one through the use of one or several switches turn on/off the gain cut? Link to comment Share on other sites More sharing options...
Members wagdog Posted January 24, 2009 Author Members Share Posted January 24, 2009 But as you say the single channel as in the modded V18 works just fine- I played a gig Sunday night with my Soldano-ized V-18 and brought along some pedals "just in case" but I didn't need them at all so I unplugged them after the first set. I have never had so much fun playing an amp which was so responsive to my playing, and to the settings of the controls on the guitar (a PRS SE Singlecut w/ a BurstBucker 2 in the neck and a BurstBucker Pro in the bridge- a guitar that smokes my Gibson Les Pauls...) Steve Yeah, it's sweet man. I took my v18 to my gig last week as the other side of my stereo rig, it sounded great. It's just an amazing amp. I've got to replace the stock speakers though, they are truly crap. This rig does sound best when cranked up though. I used the SLO-V33 head not too long ago at a gig in the same capacity. It too is a great amp. I can't believe I got the pair of these for less then $300. FWIW, I didn't wire in the bright switch on the v33h either and I've taken it off on the v18 and the bright cap. I found I was never using it, even with humbuckers. Link to comment Share on other sites More sharing options...
Members SciHi Posted January 24, 2009 Members Share Posted January 24, 2009 Well I wasn't expecting a full conversion back to stock at the flick of a switch, but could one through the use of one or several switches turn on/off the gain cut? I posted some observation on simple mods to clean up the v18 over on TGP: http://www.thegearpage.net/board/showpost.php?p=5417154&postcount=9 I really can't imagine anyone would want to go totally back to stock. Clean up the muddy overdrive, and clean tones are much easier to access, such as with a boost cut switch... Reverse engineer Steve's crunch switch (v33 clean to crunch), and add a resistor to ground near that RC circuit, and I would bet the results would be dramatic. Link to comment Share on other sites More sharing options...
Members Edge11 Posted January 24, 2009 Members Share Posted January 24, 2009 Hey steve are you ever gonna do the bogner ecstacy mods for the v33? Link to comment Share on other sites More sharing options...
Members Edge11 Posted January 24, 2009 Members Share Posted January 24, 2009 any onw have sound clips of the finished version?Will this mod work on the combo version *is it the same pcb?*how do you discharge the caps and what wattage resistors do you use? Link to comment Share on other sites More sharing options...
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