Members pomegranite Posted April 13, 2015 Members Share Posted April 13, 2015 I just traded for a Peavey Royal 8 5 watt tube amp that has headphone out. I tried it with some headphones and HOLY %#^# ITS LOUD!!! No way you could use it with headphones. I've never seen that on a tube amp before and now I know why! It's like is just a preamp out, what could I use it for since its no good with headphones? Link to comment Share on other sites More sharing options...
Members onelife Posted April 14, 2015 Members Share Posted April 14, 2015 Does it cut off the speaker when you plug the phones in? Can you use the Master volume control to tame the loudness? Perhaps you could use it as a line out to plug into a mixer for recording or to feed a PA. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 14, 2015 Members Share Posted April 14, 2015 Headphone outs don't normally double as line outs on pro gear unless the circuit is designed for that application. You commonly find the combo jacks on keyboards and laptops where the signal can be adjusted down from headphone level to line level with an attenuator. Normally you might not damage something that's plugged into a headphone jack but the signals at least 10X hotter then line level and may distort. They do make attenuators you can use to drop the level -10~20db to get it down to line level. The headphone jack in this case may be a matter of using the right headphones. On a tube amp, I'd likely guess the impedance is a match for low impedance headphones of around 8 ohms. Many consumer headphones are 32 or 64 ohm and highly sensitive so they can be run with a really weak signal source. Something like my AKG headphones would likely sound normal because they are designed to run with a much higher pro signal level. Try what onelife suggests, turn the master volume down and run your preamp up. If the headphones are tied into the speaker jack, this should attenuate the signal down. If the signal is tapped before the power amp then the only way to bring the level down is by getting less sensitive headphones or adding attenuation. This would involve making a box with a couple of jacks and a dual pot to cut the signal level down. If you can solder, Its a pretty simple job, no harder then wiring up a pot in a guitar pot. I'd think a 10K pot would be sufficient to attenuate the volume down. You could build the pot into the amp as well and use it to adjust between line level and headphone level. Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 14, 2015 Members Share Posted April 14, 2015 I have a 15w Crate with a headphone out and it is F***ing loud. Works exceptionally well as an overdrive. The speaker does cut out though and that's no good right? Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 14, 2015 Members Share Posted April 14, 2015 I have a 15w Crate with a headphone out and it is F***ing loud. Works exceptionally well as an overdrive. The speaker does cut out though and that's no good right? It doesn't make allot of sense not to have the speaker turn off when using headphones. My little Marshall has a headphone jack that's not switched and the speaker doesn't turn off which is kind of stupid. Why would you need headphones with the speaker going? Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 14, 2015 Members Share Posted April 14, 2015 It doesn't make allot of sense not to have the speaker turn off when using headphones. My little Marshall has a headphone jack that's not switched and the speaker doesn't turn off which is kind of stupid. Why would you need headphones with the speaker going? Doesn't that help cook the transformer ? Link to comment Share on other sites More sharing options...
Members onelife Posted April 14, 2015 Members Share Posted April 14, 2015 I have a Fender Mustang and, according to the manual, the headphone out (mini phone jack) doubles as a stereo line out. It's the same with my Boss ME-25 pedal although the jack is 1/4". Of course these are not tube amps. I also have a small Blackstar 1 Watt tube amp, which uses a 12AU7 dual triode in push pull configuration as the final. It too has a headphone jack that is setup to double as a line out. Randy Bachman used to use a Fender Champ as a preamp to drive a bigger amp until Gar Gilles (of Garnet amps) told him he it was dangerous and built him the "Herzog" which was essentially a Champ with a built in power resistor instead of a speaker and a footswitchable bypass control. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 14, 2015 Members Share Posted April 14, 2015 Doesn't that help cook the transformer ? Not on most solid state amps. most can run without a load and if it has a master volume you can even turn the power amp off. (if the headphone tape in before the power amp) If its a tube amp it would need to switch over to a high wattage ceramic resistor to take the place of a speaker load when the speakers come off line. You cant run most tube amps without a load without cooking the power tubes. The headphone jack may be connected to the output but the drop down resistors wouldn't be enough to substitute for the speakers. You'd never want to connect headphones to a speaker jack, not only because you'd only have one side of the headphones running on a mono jack but the headphone wattage is super low, usually in the miliwatts and can blow just powering the amp on. If the headphones tap into the preamp, then they wouldn't serve as an output load at all, but with a master volume you could turn the volume down on the power amp and mute the speakers without removing them from the circuit. Then just use the preamp settings to adjust for your headphone levels. I'm not a real big one for headphone jacks on amps myself. I use the one on my practice amp occasionally to hear fine details setting up ma guitar but that's about it. I have better options if I needed to use headphones including a headphone amp connected to my recording setups in the studio. I can then just dial up my sound with preamps and effects units for recording and not even have to mess with the amp. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 14, 2015 Members Share Posted April 14, 2015 I have a Fender Mustang and, according to the manual, the headphone out (mini phone jack) doubles as a stereo line out. It's the same with my Boss ME-25 pedal although the jack is 1/4". Of course these are not tube amps. Those are one of those exceptions I mentioned. Like I said they are common is consumer stuff and finding their way some amps and gear. Its something people want so why not make it an option. Its not that hard to design a jack like that which will do double duty for line out and headphones, but the quality does suffer a bit. A regular headphone jack usually has less attenuation so you have more power to drive headphones and get better fidelity. The Mustang boasts Speaker emulated line out so that attenuation which colors the sound is having a beneficial effect from that vantage point. I used to try using headphone jacks off Hi Fi gear to record stuff as a kid and since those jacks took the signal off the power amp they sucked for that purpose. You'd get a bunch of noise from the power transistors and power supply when you try and turn the volume down to get something close to line level. There's much to do about hitting the sweet spot on analog gear too. You can turn volume down so the headphone jack doesn't distort a line feed but the fidelity of the sound really sucks when turned down that low. The noise floor is much to high. With a preamp line out, you may be cranking the preamp up to maybe 50% and getting a nice juicy sound. This is the big issue running analog gear because just about all analog gear has a sweet spot. Just being able to make something work is one thing, but getting the best fidelity is another. Some line outs like on Hi Fi gear isn't affected by the tone and volume controls. The line out comes before those knobs so you get 100% fidelity from the inputs. This way you can loop an EQ in there and get maximum fidelity changes. In other gear like PA stuff its not uncommon to have line outs before and after the EQ or volume sections. An insert is preamplified for direct recording at line level or looping a single effect off the mic. Monitor sends are line level and usually come before the channel volume. This allows you to turn the mic off and still hear the stage monitors. Then you have effects send loops like you'd have in a guitar amp. Those can be before or after the channels EQ and sometimes have a pre and post button. Then you may have Aux sends which are line level which let you send several mics to a single line out for recording. Then the mains and aux mains are all line level outs, and even line outs specifically for recording a stereo signal or playing back audio devices. All of these taps in the amplifier chain have been used for a long time and really haven't changed much over the years. They have been getting incorporated into guitar amps because Guitarists have a valid need for them recording and live. I wouldn't doubt Blue tooth will be big too as it is in Pro audio gear already adding a digital recorder with an external mic jack for recording the rest of the band isn't so far from your old Ampeg amps that had an instrument, Mic and Accordion input, except the recorder would be a whole lot more useful. The only thing they haven't added is having some AI robot play the instrument for you making the musician obsolete, Woops they are doing that too. How about a guitarist with 72 fingers coming to your local club. The Japanese live this stuff http://www.cnn.com/2014/03/14/tech/m...bot-guitarist/ Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 15, 2015 Members Share Posted April 15, 2015 JFTR my Crate's a twin el84 supposedly class A bedroom amp that stopped working a couple yrs back. It sounded liek schitt acoustically but It did make a wonderful grindy OD. I think the headphone out (whyTF they included I don't know) is deliberately over juiced so you don't cook the amp. Evidently I did by using it as an OD. Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 15, 2015 Members Share Posted April 15, 2015 Incidentally it wasn't the tubes that failed. It just wont turn on anymore. I couldn't find anything that looked like a fuse so it's now furniture. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 15, 2015 Members Share Posted April 15, 2015 How did you use it as an overdrive? Connecting it to some other piece of gear? I can see that feeding another piece of gear with a hot signal, causing the components to overheat and blow, but I don't think that would hurt the amp unless you fed it back into the amp some how. If you were using it when the amp blew It likely affected the output or power transformer. I'd think with the step down resistors to the headphone jack would be enough to prevent the power transformer from being overloaded though. I'm not a huge fan of Crate amps myself. I haven't found any that sounded very good to me. I have one of their bass heads right now. Its a solid build but has a crap tone stack and EQ. It sounds OK with their own cabs but sounds awful on any other cabs I've tried. Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 15, 2015 Members Share Posted April 15, 2015 I used it just like a pedal; straight into the guitar input of my rig. It did sound very good that way. For sure better than the speaker and almost better than any other OD I have. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 15, 2015 Members Share Posted April 15, 2015 So it was the headphone jack driving another amp. The only thing I could see is if the amp didn't have a load and you were running just the headphone jack, the tubes could have fried and taken out a transformer, or if you're lucky a tube or fuse. It was most likely using that jack as a line send that caused the problem. That jack isn't designed to distort and its component tolerances aren't designed to take that abuse. The jack likely needs to see a low impedance of maybe a few hundred ohms. Connecting it to another amp with a high impedance is like running it with no load at all, and as I've said before, running a tube amp with no load will blow the power amp. The whole idea is to have matching impedance so you get maximum fidelity. I have blown out headphone preamps before abusing them using multiple sets of headphones. You don't know if the component tolerances can candle the extra load. When it blows out you know it cant for sure. In some cases it can cause a slow death, instant death or it may be durable enough to survive. A good tech using the proper tools to monitor what's going on in a circuit could tell you if the current draw is dangerously high. An engineer could tell you if its a mathematical possibility based on the manufacturers specs. As a novice, distortion from a device that's not supposed to distort tells you its being abused. From there you run it at your own risk. It was likely one amp or the other would blow and its usually the one with low tolerance or inferior components will blow. In this case it was the crate. Don't feel bad though. I cant count the number of blowouts I created over the years before I got my degree in electronics and actually knew what I was doing. Some of the coolest sounds I ever got were out of old Tube Tape recorders driving a guitar amp. I'd connect a guitar cord to the playback head wires, set the deck for play, then run the line out into a guitar amp. The playback head is essentially an electromagnet much like a guitar pickup is. It detects magnetic changes in the tape. The difference is it uses extra gain stages to boost the volume up. When you connect a guitar pickup to it and crank the playback volume up, you get that blown out "Spirit In The Sky" type overdrive that sounds like your running a 100w head into a small speaker on the verge of smoking. That's another cool but dangerous way of getting great drive. Using a high watt amp and cranking the speaker beyond its limits. A speaker can sound killer when you overdrive them to the verge of blowing. Unfortunately, its very easy to overheat and deform the voice coil trying it so I don't suggest you try it unless you're willing kiss that speaker goodbye. I used to do it with old car speakers. Either the coil would fry or the paper would blow apart in chunks. The change in tone as the paper begins to disintegrate leaving only the piston and spider moving is quite interesting. It winds up sounding like a rattle snake at the end. This is important reading anyone in music should understand. Since you've already been there its good to know why it failed. There's some technical stuff in there but you should be able to gather enough details to know what its important to match impedance. Both the source and load need to be properly balanced or that energy is going to go some place and heat up something it isn't supposed to. If you intentionally abuse the balance to get distortion as an effect, you have to be sure the components can take the abuse without overheating and blowing out. http://www.soundonsound.com/sos/jan0...ceworkshop.asp Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 15, 2015 Members Share Posted April 15, 2015 As far as distortion goes, I have 40watts of Boogie and 2 Carvin 12s. Any grind I get from the power stages is incidental and already too friggin loud. I wasn't thinking impedance though. My initial motivation was plugging it in the rig, a Boogie V Twin rack pre in this case, ( this one is solid state) was the only way to audition the headphone out. I use ODs only as tone generators so there's no overt stress downstream. Seemed good to go. Link to comment Share on other sites More sharing options...
Members onelife Posted April 16, 2015 Members Share Posted April 16, 2015 JFTR my Crate's a twin el84 supposedly class A bedroom amp that stopped working a couple yrs back. It sounded liek schitt acoustically but It did make a wonderful grindy OD. I think the headphone out (whyTF they included I don't know) is deliberately over juiced so you don't cook the amp. Evidently I did by using it as an OD. I've got a Crate with four EL84s on my bench right now - the power switch failed and the owner wired the amp as if the switch was always on. The amp has a fuse on the PCBoard. He brought it in because the signal drops out intermittently and, at this point, I believe the jack for the FX loop and/or the jack for the channel switching foot pedal need to be resoldered - which involves removing the PCBoard (not something I am looking forward to doing). Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 16, 2015 Members Share Posted April 16, 2015 I've got a Crate with four EL84s on my bench right now - the power switch failed and the owner wired the amp as if the switch was always on. The amp has a fuse on the PCBoard. He brought it in because the signal drops out intermittently and, at this point, I believe the jack for the FX loop and/or the jack for the channel switching foot pedal need to be resoldered - which involves removing the PCBoard (not something I am looking forward to doing). Hey that could be something. Mine has a red backlit rocker switch that first the light would be intermittent and eventually powering up got glitchy. The amp finally stopped working but never sounded like it was in distress. I remember thinking the fuse was on the switch but I couldn't figure the wiring so I just put the amp aside. I'll have another look at it. Thanks! Link to comment Share on other sites More sharing options...
Members WRGKMC Posted April 16, 2015 Members Share Posted April 16, 2015 I've got a Crate with four EL84s on my bench right now - the power switch failed and the owner wired the amp as if the switch was always on. The amp has a fuse on the PCBoard. He brought it in because the signal drops out intermittently and, at this point, I believe the jack for the FX loop and/or the jack for the channel switching foot pedal need to be resoldered - which involves removing the PCBoard (not something I am looking forward to doing). My Buddies Crate bass amp had problems with those crappy plastic PC mount 1/4" jacks too. I fixed it for him once and even epoxied the jack in place but he wound up tugging it loose again playing on stage. I was going to replace it for him again but he wound up buying a Fender BXR 300 bass head from me for $150 instead. This gave him an extra 100 watts and his sound quality jumped two fold in the process. I only paid $100 and did a little clean up and an AC cord replacement. I took that money and bought an Ampeg Portaflex head so we both made out well. Link to comment Share on other sites More sharing options...
Members pomegranite Posted April 17, 2015 Author Members Share Posted April 17, 2015 I could use this amp as a pedal? Link to comment Share on other sites More sharing options...
Members 1001gear Posted April 18, 2015 Members Share Posted April 18, 2015 lol I just answered the one in the GF not realizing this was your thread. Link to comment Share on other sites More sharing options...
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