Hi, I am planning out a low watt amp build, but am not well schooled in circuit designs, what can and can't be done, and even if it can be done, is it really such a good idea? I've been doing a ton of reading, looking at features of both production and custom amps, picking features that I know I want and some that just sound like good ideas. My head is spinning from it all, so I thought I'd put down some ideas and see which ones stick with you guys.
I'm looking to do more stereo /panning stuff, so flexibility in blending and I/O is important. So I want to do a common thing with many, which is to have two main sounds in one enclosure. In my case a super clean Blackface and a PLEXI with extra gain to take it to JCM800 territory. There's other stuff I will describe and ask if you folks are willing to walk through it with me! Starting here, what general setup is best? I came up with three options.
a) One amp with two pre-amp channels? (I would want two inputs, and two sets of speaker outs to run separate cabs.) Other "features" would be a buffered loop (one for each channel.) Also a line out for each. If both inputs in use, blending can happen with the independent volume controls, with yet another, separate set of speaker outs (that's three sets of two (4,8,16) outputs!)
b) Two Separate amps in one head shell. Two sets of speaker outs for each. How much can the amps share? Rectifier, tranny, etc? Or is it better if they share no components? Need to blend the amps somehow, preferably in board. I know there's all sorts of outboard gear, but trying to keep things tidy as possible.
c)A two separate pre amp set up in one head shell. Outputs and options as noted above. Each pre amp with two sets of speaker outs, line outs, buffered loops. My understanding is you can connect the output of the pre amps to either the main input of a clean amp (I have a Vibroking that I think would do it) or into the fx return of any amp. Using the line out, I could also plug into a mixing board/PA when needed.
The separate amps appeal the most for maximum flexibility, and also using the family of tubes best suited for each sound from each amp. No sharing of circuits and tubes, without different gain stages etc to differentiate the tones from each channel. Does that partially explain the main difference between one amp, two channels, vs two one channel amps? Thanks, I'm sure my questions/posts will get shorter after I get through the "big questions." Thanks again.
I'm looking to do more stereo /panning stuff, so flexibility in blending and I/O is important. So I want to do a common thing with many, which is to have two main sounds in one enclosure. In my case a super clean Blackface and a PLEXI with extra gain to take it to JCM800 territory. There's other stuff I will describe and ask if you folks are willing to walk through it with me! Starting here, what general setup is best? I came up with three options.
a) One amp with two pre-amp channels? (I would want two inputs, and two sets of speaker outs to run separate cabs.) Other "features" would be a buffered loop (one for each channel.) Also a line out for each. If both inputs in use, blending can happen with the independent volume controls, with yet another, separate set of speaker outs (that's three sets of two (4,8,16) outputs!)
b) Two Separate amps in one head shell. Two sets of speaker outs for each. How much can the amps share? Rectifier, tranny, etc? Or is it better if they share no components? Need to blend the amps somehow, preferably in board. I know there's all sorts of outboard gear, but trying to keep things tidy as possible.
c)A two separate pre amp set up in one head shell. Outputs and options as noted above. Each pre amp with two sets of speaker outs, line outs, buffered loops. My understanding is you can connect the output of the pre amps to either the main input of a clean amp (I have a Vibroking that I think would do it) or into the fx return of any amp. Using the line out, I could also plug into a mixing board/PA when needed.
The separate amps appeal the most for maximum flexibility, and also using the family of tubes best suited for each sound from each amp. No sharing of circuits and tubes, without different gain stages etc to differentiate the tones from each channel. Does that partially explain the main difference between one amp, two channels, vs two one channel amps? Thanks, I'm sure my questions/posts will get shorter after I get through the "big questions." Thanks again.
For low watt, what do you mean? 15-18 watts, 5 watts? My initial thought would be a two channel amp voiced differently to get your sound that you want. If this is your first build, it might be best to keep it a little simpler than to do stereo, FX loops, panning,etc. Learn about lead dress, minimizing noise and hum, layout procedure, grounding schemes, etc. And not book learning, actual building experience. Do a Fender Blackface style channel and a second higher gain channel. This probably will be the most you want to do at first.
Some people might even suggest you do just a single channel amp with maybe 2 preamp tubes and either one or two power tubes depending on your power needs. It usually is a mistake to take on too much at first. Maybe a Lite IIb type amp and then graduate to more later. Just my opinion but I've heard it many times.
Some people might even suggest you do just a single channel amp with maybe 2 preamp tubes and either one or two power tubes depending on your power needs. It usually is a mistake to take on too much at first. Maybe a Lite IIb type amp and then graduate to more later. Just my opinion but I've heard it many times.
I think the only real reason to have 2 amps is for stereo effects. In that case you'll need to think about how you're going to manage that now. Footpedal? I would have thought identical amps in that case.
If you want different tones, then the modern approach is to use some kind of processor somewhere in the chain and switch tones using that. One amp would do, but you could have different processing for each path. Each amp must have it's own speaker, but 2 solid-state amps could share a common power supply, as could 2 tube amps, but that might be less desirable.
You could have 2 proprietary amps from different manufacturers, if you wanted particular tones, but better to buy them off-the-shelf.
The very last kind of option is to attempt to build 2 tube amps each to to meet a different 'sound' requirement and integrate that into a single device with roughly the same volume on each channel, which seems to be where you're headed.
Why not just assemble something like what you want with some borrowed gear and see if it lives up to your expectations. You could split the signal to 2 swell pedals, each to an amp. I would have thought you could mess around with this 'virtually' with a computer, soundcard and some plugins.
If you want different tones, then the modern approach is to use some kind of processor somewhere in the chain and switch tones using that. One amp would do, but you could have different processing for each path. Each amp must have it's own speaker, but 2 solid-state amps could share a common power supply, as could 2 tube amps, but that might be less desirable.
You could have 2 proprietary amps from different manufacturers, if you wanted particular tones, but better to buy them off-the-shelf.
The very last kind of option is to attempt to build 2 tube amps each to to meet a different 'sound' requirement and integrate that into a single device with roughly the same volume on each channel, which seems to be where you're headed.
Why not just assemble something like what you want with some borrowed gear and see if it lives up to your expectations. You could split the signal to 2 swell pedals, each to an amp. I would have thought you could mess around with this 'virtually' with a computer, soundcard and some plugins.
Thanks for Replies
This is my first custom build (haven't picked the builder yet,) and am used to the common configurations on production amps. So, like any special order, I want to be as certain as I can that I choose the best sonic combinations when not limited by what a factory produces. boobtube, you are right, I have little live rig routing experience, but I do have some. I have developed likes and dislikes with gear and brands, and discovered what options are important to me by their absence in my present gear. So, like many, I want to roll all that into a custom amp order with a quality builder. Low watt means 5-8 watts. Counterculture, I get the "don't get over your head" comment, I really do. I think I need to back up a step and get an understanding of muti channel amp voicing v. Separate single channel amps. Example, Phaez amps builds a "Duophonic" which has two channels, voicing of your choice. In my case, one would be Blackface clean (Corona,) and the Pasadena (hotter SIBLEY and Jackal voicing.) Would the Duphonic Corona channel sound exactly as the standalone single channel Corona? Same question on the second Pasadena channel? If yes, that's where I am getting a little lost. How does such an amp get the exact tones from a shared set of rectifier, tranny, power tubes, etc? when as standalone they use different tubes, guts, etc? OK, so through some creative circuitry it gets done.
Then there are I/O considerations. I would like to have two sets of speaker outs for each channel, so I can set out a couple of 1x12's spread out a) one signal from one channel split to the two cabs b)same for the second channel. c) One channels tones to one speaker, the other channels sound to the second cab. d) something outboard to mix the sounds into one, which is split between the two cabs. I have rarely, if ever, seen the number and separate outputs for amp channels on a multi channel amp. I see multiple speaker outs on stand alone heads regularly.
That's what made me think of two independent amps. They will theoretically sound as expected, as they will use their own set of unique tubes as in the line of amps they are inspired by, and have all the I/O options I will need (or can easily specify in the build.) Put both in an oversized head shell and off I go. Is there a "primer" on multi channel amps and how they duplicate multiple tones from one set of parts/guts? Thanks, Andy
This is my first custom build (haven't picked the builder yet,) and am used to the common configurations on production amps. So, like any special order, I want to be as certain as I can that I choose the best sonic combinations when not limited by what a factory produces. boobtube, you are right, I have little live rig routing experience, but I do have some. I have developed likes and dislikes with gear and brands, and discovered what options are important to me by their absence in my present gear. So, like many, I want to roll all that into a custom amp order with a quality builder. Low watt means 5-8 watts. Counterculture, I get the "don't get over your head" comment, I really do. I think I need to back up a step and get an understanding of muti channel amp voicing v. Separate single channel amps. Example, Phaez amps builds a "Duophonic" which has two channels, voicing of your choice. In my case, one would be Blackface clean (Corona,) and the Pasadena (hotter SIBLEY and Jackal voicing.) Would the Duphonic Corona channel sound exactly as the standalone single channel Corona? Same question on the second Pasadena channel? If yes, that's where I am getting a little lost. How does such an amp get the exact tones from a shared set of rectifier, tranny, power tubes, etc? when as standalone they use different tubes, guts, etc? OK, so through some creative circuitry it gets done.
Then there are I/O considerations. I would like to have two sets of speaker outs for each channel, so I can set out a couple of 1x12's spread out a) one signal from one channel split to the two cabs b)same for the second channel. c) One channels tones to one speaker, the other channels sound to the second cab. d) something outboard to mix the sounds into one, which is split between the two cabs. I have rarely, if ever, seen the number and separate outputs for amp channels on a multi channel amp. I see multiple speaker outs on stand alone heads regularly.
That's what made me think of two independent amps. They will theoretically sound as expected, as they will use their own set of unique tubes as in the line of amps they are inspired by, and have all the I/O options I will need (or can easily specify in the build.) Put both in an oversized head shell and off I go. Is there a "primer" on multi channel amps and how they duplicate multiple tones from one set of parts/guts? Thanks, Andy
So you are wanting to know what is possible to determine what features to ask your builder to put in your custom amp? You said "haven't picked the builder yet". If that is the case, you should direct your questions to him. He will be the one to determine what he can build and what he can't. When I answered to keep it simple for your first build, I assumed you were the builder. If you want to dream big, ask your builder what he/she is capable of doing. You should find a very talented one to pull off what you want. I tend to agree with sreten, a little over complicated.
I must admit this is the first thread that the OP is asking about what another builder can do. Unless I have misunderstood.
I must admit this is the first thread that the OP is asking about what another builder can do. Unless I have misunderstood.
I also am looking at building a 4-7 watt guitar amp. I’ve read in forums about the idea of using two halves of the same 6v6 in triode mode. The idea would be to keep the punchiness of the push-pull plexi circuit rather than going single ended to get the lower output. Alternatively I’m thinking of building a 6v6 plexi with two 6v6s and putting a triode/pentode switch. Any thoughts or suggestions? I’ve never had an amp with a triode/pentode switch. Who can tell me beyond the volume change how would you describe the change in tone. I hear the 6v6 is very inefficient in triode mode, will that mean huge tone suck too or mostly volume drop.
A 6V6 has no halves.
Go read everything Rob Robinette has written on valve amps. Start at the top and work your way down.
Then take your new-found understanding and go play a bunch of amps/speakers to find out what sound you actually want.
If it is a JCM800/JCM45 sound you want then the 5F6A-M Bassman Micro© Guitar Amplifier is a good place to start. It is likely to still be too loud.
You'll still need some appropriate speakers.
Ok. I'm going to stop quoting there.
Go read everything Rob Robinette has written on valve amps. Start at the top and work your way down.
Then take your new-found understanding and go play a bunch of amps/speakers to find out what sound you actually want.
If it is a JCM800/JCM45 sound you want then the 5F6A-M Bassman Micro© Guitar Amplifier is a good place to start. It is likely to still be too loud.
You'll still need some appropriate speakers.
Where do you plan on playing this amp? For an experienced builder it might not be too big a deal. First thing I thought of is using Iron from 60's console stereos. But the requirement of a clean channel with the same wattage as the dirty channel doesn't make sense, well unless you want one watt output from the Marshall. Depending on how loud you want either and how clean is clean will specify how much power you need. Will you be playing one at a time or mixing the two? Or would a stereo rig that is clean enough for a BF sound be better and you can mix a Marshall and Fender together, send one to each side, switch between them sending to both or just to one side.
You can approach it as two different preamps as you would a two channel amp with a clean and distorted sound. Send them out and return separately and either bring them in separately and then go to their respective power amp, or mix them as a stereo signal, or do a stereo clean and then as in selecting a lead channel, the Marshall signal goes out in stereo.
Draw up a signal path that you want as in building blocks. Not a good diagram but a quick search did not bring up any better.
You can approach it as two different preamps as you would a two channel amp with a clean and distorted sound. Send them out and return separately and either bring them in separately and then go to their respective power amp, or mix them as a stereo signal, or do a stereo clean and then as in selecting a lead channel, the Marshall signal goes out in stereo.
Draw up a signal path that you want as in building blocks. Not a good diagram but a quick search did not bring up any better.
An externally hosted image should be here but it was not working when we last tested it.
I done gone fergit to comment on that bit.
Figure at least 10db. In english, 2W (nominal) of clipped PP is actually 4W of delivered which means your clean-clean-clean channel needs at least 40W. If you really mean "Fender clean" then you might get away with 10W, presuming an all tube approach.
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