Very cool! Do you have a schematic?
I have never heard of 6LU8 tubes so I will look into those.
There's a ton of knowledge showing up in this thread! I too am interested in a SS guitar amp project...but........
Here's my unsolicited 2 cents—to a self described "never-built-an-amp-er" @Megatrab.
I'm a guitar player who's made from scratch to date 10 tube guitar amps (all different topology combinations in increasing complexity, from Fender Champ to Dumble and Trainwerck)—and 20+ hi-fi amps and preamps and related components in my vinyl based playback system...(and built my own guitars too...)
Start small, start basic, build a simple tube amp like the Fender 5F1 "Champ" (lots of kits around). It won't cost an arm and a leg—even if it's real life parts cost is more than a SS amp, it will be practically guaranteed to work on first fire-up and sound great—it will be yours—and the 5F1 gets way way loud—perhaps not gigging loud, definitely too loud for any normal room in a house—but after you build the 5F1, you build the 5E3/Fender "Deluxe" (Neil Young, The Edge, etc. Also lots of kit around)—and that's fully gig-able. Be afraid of the high voltage yes—like a table saw—follow some rules and there's very little risk for a careful human—this methodology will help you for any type of amp work. You can even ditch the rectifier tube for some savings and make that part solid state if you want—it will change the feel of the amp—not good, not bad. (keep your speaker for another project down the road.)
In terms of real world costs... guitar amps are similar to hi-fi amps—the most expensive single piece is the chassis or cabinet. I make my own on both counts and that's the only reason I personally could sneak in under retail costs—otherwise there's no real point to doing any of this for cost savings. Rather, you do it because you can—you have to—it brings you joy—it's more fun than buying some stuff—and you can learn and tweak and make it your own....
And no offense to the beyond incredible DIYaudio.com crew—you know I love you—but the three sites below are were the instruments amps reign in terms of projects and specific amp knowledge/feedback/support/ideas—on the interwebs—this info is for the OP:
https://robrobinette.com/ (The amount of information and projects here for the noob is invaluable, worth looking at for hi-fi general knowledge too)
https://www.tdpri.com/ (All other amps not listed below—mostly Fender, but there's everything else here too)
https://ampgarage.com/ (Trainwreck and Dumble)
Some inspiration attached, Fender Champ and a "Deluxe"....The last image is a Dumble—it's NUTS but does sound incredible outside or in a big big space.
Here's my unsolicited 2 cents—to a self described "never-built-an-amp-er" @Megatrab.
I'm a guitar player who's made from scratch to date 10 tube guitar amps (all different topology combinations in increasing complexity, from Fender Champ to Dumble and Trainwerck)—and 20+ hi-fi amps and preamps and related components in my vinyl based playback system...(and built my own guitars too...)
Start small, start basic, build a simple tube amp like the Fender 5F1 "Champ" (lots of kits around). It won't cost an arm and a leg—even if it's real life parts cost is more than a SS amp, it will be practically guaranteed to work on first fire-up and sound great—it will be yours—and the 5F1 gets way way loud—perhaps not gigging loud, definitely too loud for any normal room in a house—but after you build the 5F1, you build the 5E3/Fender "Deluxe" (Neil Young, The Edge, etc. Also lots of kit around)—and that's fully gig-able. Be afraid of the high voltage yes—like a table saw—follow some rules and there's very little risk for a careful human—this methodology will help you for any type of amp work. You can even ditch the rectifier tube for some savings and make that part solid state if you want—it will change the feel of the amp—not good, not bad. (keep your speaker for another project down the road.)
In terms of real world costs... guitar amps are similar to hi-fi amps—the most expensive single piece is the chassis or cabinet. I make my own on both counts and that's the only reason I personally could sneak in under retail costs—otherwise there's no real point to doing any of this for cost savings. Rather, you do it because you can—you have to—it brings you joy—it's more fun than buying some stuff—and you can learn and tweak and make it your own....
And no offense to the beyond incredible DIYaudio.com crew—you know I love you—but the three sites below are were the instruments amps reign in terms of projects and specific amp knowledge/feedback/support/ideas—on the interwebs—this info is for the OP:
https://robrobinette.com/ (The amount of information and projects here for the noob is invaluable, worth looking at for hi-fi general knowledge too)
https://www.tdpri.com/ (All other amps not listed below—mostly Fender, but there's everything else here too)
https://ampgarage.com/ (Trainwreck and Dumble)
Some inspiration attached, Fender Champ and a "Deluxe"....The last image is a Dumble—it's NUTS but does sound incredible outside or in a big big space.
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I have used the amp with 8 and 16 ohm speakers.
It’s slightly quieter with 16 ohm but still really loud
Thank you for the advice and links.
I am very familiar with all of those sites. I have a TDPRI and AmpGarage account. I’m also on the SLOforum which has tons of info about Soldano and hot rodded Marshalls.
I also appreciate the take on “build a simple amp first”. I get why that would be good advice but it’s not really the direction I want to go in.
I genuinely want to build a solid state amp, but it sounds like most people think that’s a bad idea.
I have a lot of great replies here so I’ll need to do some reading, reflecting, pricing, and planning.
The biggest thing that I have a hard time with is figuring out what transformer I need.
So, I need to do more reading about that.
This is my guitar amp project for now. I actually started it a while back and had to shelve it for a bit. I did it on a sort of challenge from a guy I knew. The challenge was ( and he really was joking at the time). Why don't you make a guitar amp using those funny looking TV tubes. I chuckled and didn't say another word. When I went home that night, I went to my 1 shed, got the chassis, power and output transformers. Went to another shed started digging up tubes. I already had the pots and various other components in my work room. So, I sat down at the bench, laid it out and started cutting holes. I wanted to use all Compactron's and Novar's tubes but there were a couple I couldn't find. for one the rectifier. I am going to make another stab at find a Compactron rectidfier. If not, I will have to use the 5Y3WGT that I have mounted right now. The input tube is a 6AC10 like in the old Ampeg Jet. The other preamp tube is a 6U11. The 2 small 9 pins behind the input tubes are 5670's for the active tone and the output tubes are 6GF7's. The 6AC10 and the 6U11 are triple triodes. The 5670's are dual triodes and the the 6GF7's are dual triodes. One section is a low level triode the other is power. One of the low level triodes in the output tubes will be a cathodyne phase inverter the other low lever will be the reverb tank driver. The amp will have input gain, Master volume, bass,mid and treble active tone controls and reverb send and return. It should have around 12 to 14 Watts output with a nice tank reverb. I have some other trick I think I am going to throw in later. Telling your buddy to set up on a spread sheet is a good idea. For me though, I carry my spread sheet and schematics in my head. It helps to have an Eidetic memory. This is kind of the Dumble method of amp building. Now I don't know if he watched me or the other way around. Anyway, we both had the same belief in amp design. I don't want to build a Boutique knock off of an AC-15 or30 like Bad Cat and so many others. Each one is different and they all sound great. One thing I don't do that he did was fill the amps up with goo when I get it done. Oh yea, the speaker for this amp is an old single 10 Silvertone cabinet with a Jensen Blue Frame in it. I bought the cabinet over 20 years ago at a guitar swap meet in Phoenix. Bought it for $50 and the Jensen was good. I do a lot of that or at least I did. IO have a lot of bare NOS chassis, at least a half ton of old Iron, around 20.000 tubes( use to have 5 time that amount but had to sell a bunch of them when my Wife got really sick). I have been at this since I was 11 Years old and I just turned 70 last month... So, there's a bit for ya. Oh yea, one other thing I wanted to mention. You talked about The Gorilla amp. Back in the 80's I( went in the studio with my band at the time and we produced an EP. The only amp the guitar player used was one of those Gorilla's. Anyway so, there you are. Good to meet you.
Best Regards,
Jamie
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IMHO, if you want to build an amp, build and amp and have fun, and don't electrocute yourself. This website is called "DIY" yet the threads often get hijacked into a tone completely at odds with that ethos. Build a crappy one and have fun.
Of course you can easily get a loud solid state guitar amp for peanuts - I get them for free sometimes. If you 'want' gear or electronic parts free or cheap, the key is just to not 'need' them right now. With patience you'll run across stuff like output transformers and power transformers more or less for free, and you're halfway home. If you want to spend your hard earned money on a hobby that doesn't make economic (or technical!) sense, do it. Life is short. It's too short to just drop your credit card at guitar center, or to get discouraged by certain people who will remain nameless.
Here's the schematic for an early Peavey Bandit amp - one of many solid state amps I got for free and fixed - it's pretty simple even though it has a saturation circuit, two channels footswtichable and reverb circuit - it could be simplified. You could find a "blown" amp and fix it - it can be almost as much of a pain in the neck as building one, and cheaper, and you'll learn a lot along the way.
You're right about tube amps and power ratings. The clipping of solid state amps is not acceptable sounding, so the minute they clip, it's over IMHO. I think the Peaveys were well regarded because they are very clean power amps that don't skimp on power, so you have a lot of clean headroom to put pedals in front of. Can't really think of any justification for solid state guitar amps though if you can get a tube amp powerful enough for what you need. 🤘
Of course you can easily get a loud solid state guitar amp for peanuts - I get them for free sometimes. If you 'want' gear or electronic parts free or cheap, the key is just to not 'need' them right now. With patience you'll run across stuff like output transformers and power transformers more or less for free, and you're halfway home. If you want to spend your hard earned money on a hobby that doesn't make economic (or technical!) sense, do it. Life is short. It's too short to just drop your credit card at guitar center, or to get discouraged by certain people who will remain nameless.
Here's the schematic for an early Peavey Bandit amp - one of many solid state amps I got for free and fixed - it's pretty simple even though it has a saturation circuit, two channels footswtichable and reverb circuit - it could be simplified. You could find a "blown" amp and fix it - it can be almost as much of a pain in the neck as building one, and cheaper, and you'll learn a lot along the way.
You're right about tube amps and power ratings. The clipping of solid state amps is not acceptable sounding, so the minute they clip, it's over IMHO. I think the Peaveys were well regarded because they are very clean power amps that don't skimp on power, so you have a lot of clean headroom to put pedals in front of. Can't really think of any justification for solid state guitar amps though if you can get a tube amp powerful enough for what you need. 🤘
You know, my advice to you. Go see if you can find a HAM Radio operator or a HAM club in your area. They typically have swap meets once or twice a year. You would be surprised what I have found at those meets. Also, check thrift stores for old tube organs especially the old Hammond's like the model M-110 or an old Baldwin. The last one I bought at a thrift store here in my little town. I walked in saw the Hammond 110, looked at the price tag. $10!! I asked the girl about it and she said there is something wrong with it. So I asked if I could power it up and she told me when she brought an extension cord to me that, oh by the way, it's half price day so if you do want it, it's only $5!!! I didn't care if it did work for $5!! All the tubes were in it and the power transformer. So I plug it in, turn on the main power, give it a minute and hit the starter switch. Most people don't know that you have to start a Hammond organ like you do your car. I paid the $5 and got it out to my truck on a dollie. A guy passing by helped me load it in my truck and it was much easier to unload it. I dollied it into one of my back shops , took the back cover of and I immediately notice that one of the tubs had the top tip broken off and it had lost it's vacuum. A common tube. Went to one of my boxes of tube in the shop, got out a new one . I plugged it in, and when it warmed up. Guess what, now the Bass pedals worked. See, that's the stuff you have to look for. I just happen to have now, 60 years experience looking at all this stuff. So, there buddy. That's lesson one. Learn to scrounge...
Best Regards,
Jamie
Thank you everyone for your contributions. I know that is difficult to tell intent from words on the internet, but I really and genuinely appreciate all of it. I have learned more in past 24 hours than I have in years. Its really maddening in the best way!
I want to derail my own thread, but for the purposes of circling back. Its all relative to building amps..
1. I currently have 2 TPA3116 boards (60w@ 4ohm 24v I think?) I have a couple of companion PCBs that I got from a nice guy on the PedalPCB forum. One is just a buffer/boost and the other is a TMB and Volume board. Those will be my first amps, but I don't have the means to connect the speaker up. I have plans to finish that up this weekend and then order the power supplies.
Obviously this wont be loud enough for much. I thought they would make fun micro amps for playing at home and testing pedals.
2. Are there any solid state power amps that were designed to be pushed into clipping and end up both sounding good and not damaging anything? I am thinking soft asymmetrical clipping. Diodes?
3. Excluding Class D, Is it better to always use a PT over SMPS? Also, can someone share any information on videos or websites that help better explain choosing the right power supply?
I want to derail my own thread, but for the purposes of circling back. Its all relative to building amps..
1. I currently have 2 TPA3116 boards (60w@ 4ohm 24v I think?) I have a couple of companion PCBs that I got from a nice guy on the PedalPCB forum. One is just a buffer/boost and the other is a TMB and Volume board. Those will be my first amps, but I don't have the means to connect the speaker up. I have plans to finish that up this weekend and then order the power supplies.
Obviously this wont be loud enough for much. I thought they would make fun micro amps for playing at home and testing pedals.
2. Are there any solid state power amps that were designed to be pushed into clipping and end up both sounding good and not damaging anything? I am thinking soft asymmetrical clipping. Diodes?
3. Excluding Class D, Is it better to always use a PT over SMPS? Also, can someone share any information on videos or websites that help better explain choosing the right power supply?
I went for a 30+ watts on that one, sort of winging it, higher in wattage but same type of idea as one amp I built. It was a Bassman type of circuit, between 15-20W. Used a Deluxe Reverb transformer and a 120:120/240V 50VA transformer for the high voltage and a wallwart switching ps for the heaters. Used 12AB5's for the output tubes, a 6V6 variant shoved into a 9-pin bottle. There are also 12V6's, same as the 6V6 but 12V heaters. The tubes can be had fairly cheap. Where are you going to get a NOS 6V6 for under $7?
https://www.tubesandmore.com/products/vacuum-tube-12v6gt-tetrode-beam-power
Under $6 for the 12AB5.
https://www.tubesandmore.com/products/vacuum-tube-12ab5-tetrode-beam-power
The 12AB5 was designed for car use and operates on a wider heater voltage, might be less bothered by vibration also. I am guessing the 12V6 was also intended for car use. The transformer I used for the HV is a Hammond although the Triad NX-68 is equivalent (I think Hammond discontinued the transformer I used. Under $25.
https://www.digikey.ca/en/products/detail/triad-magnetics/N-68X/1887210
Bending sheet at home in a vice. Or get a HVAC place maybe bend a piece of scrap for you,
Used a side from a desk top computer for the chassis. Pictures are on Photobucket, should download them one day. Easier to just give the thread on the build. With a Fender Blues Jr speaker it was loud as heck.
https://www.tdpri.com/threads/inexpensive-lightweight-can-of-whoopass.478718/
Or you can make a hybrid amp, using the TPA3116 (I have a bunch and wanted to make an amp with one but with a tube preamp). Run it off a 19V laptop PS, run three 12AX7 heater's in series. I used one of these converters to get the high voltage, you can find them for around $7. The do have a bug, the rectifier can blow due to overheating, I want to put a small heatsink on it (it is under the board).
https://www.amazon.ca/DEVMO-45-390V-Voltage-Converter-Step-up/dp/B07T6L61D9
I want to try one of these for a 15-20W amp, supplied by a laptop supply again. You need one that has a ground pin also, many just have the line and neutral connections. Some other things to consider.
It’s one of those TV tubes, thats still available and around $8. Contains a pentode with more kick than an EL84 and a nice small signal triode. Not the cheapest on the planet anymore, but cost effective for what you get. Hundred (or two hundred) buck friendly. They “work” in standard topologies where pentode outputs work. Had a pair up and running on the bench with about the cheapest transformer set that you can get, and it didn’t give me any trouble. The only thing you e got to work around with these off the beaten path tubes is the fact that you have to drop the screen voltage. They are NOT happy at all running them up around near B+, hence the emitter follower for g2. This is just the simplest cheapest way to do it. SOA is an issue in the pass transistor - in theory you can use one cheaper than an MJL4281, but it is the strongest one you can get these days.
I was thinking about a dual channel amp with two pair and two speakers. When I get around to my “last guitar amp” I’m sure I’ve got the power stage covered - 30 per channel is plenty loud enough. When I want STUPID loud I have 30,000 watts of PA and building more. Most of the voicing will be in the front end, which is totally open at this point. I’ve got a fairly decent bass amp that puts out around 130 watts, driving an old vintage Pyle 18”.
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That works when it wants half the voltage. You can certainly select a tube that does want half of B+ on g2, to get the peak current you desire. Some of the stuff I was playing with wants a lot LESS than half the B+ (like 125V). Can still run off the lower half of a doubler, but you’re back to needing a regulator or follower again. Custom transformer winds lend themselves to doing this too. But it’s outside the wheelhouse of most people around here.
I would think keeping the amp as simple as needed is the way to go for a first build. I have some compactron tubes (oh why did I buy them again) but find it hard to use them as I have plenty of other more standard tubes. There is the 6CW5/8CW5/15CW5's (EL86) to make 20W. It is a lower voltage EL84, think our Tubelab tortured a few. I plan on using the Hammond OT for the Deluxe and run 3.3k rather than 6.6k primary impedance.
https://www.diyaudio.com/community/threads/6n2p-6cw5-design-with-toroidal-outputs.327541/
Here is the higher current version of the transformer I used in the 12AB5 amp. I used a 30VA transformer, this one has double the current and should work with a 30W+ amp. $22.61 Still need a heater supply.
https://www.digikey.com/en/products/detail/hammond-manufacturing/186E120/2358260
https://www.diyaudio.com/community/threads/6n2p-6cw5-design-with-toroidal-outputs.327541/
Here is the higher current version of the transformer I used in the 12AB5 amp. I used a 30VA transformer, this one has double the current and should work with a 30W+ amp. $22.61 Still need a heater supply.
https://www.digikey.com/en/products/detail/hammond-manufacturing/186E120/2358260
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Not me 😄
Quite the opposite, I find tube amps INCREDIBLY boring.
Somebody posted a few days ago: "there is not such a thing as "Guitar amp design", all are just small tweaks on 50-60 y.o. designs"
You know something? ... I fully agree!
If we are talking Tube designs that is.
New horizons, new designs, creativity, are all in the SS field ... or else.
Besides, you only want your power amp to faithfully reproduce excellent sound already created by your preamps, pedalboards, emulators, etc., why worry or care about it adding one extra sound .... to your already huge Menu?
Also think about this: SS Guitar amps outsell Tube ones 100:1
There must be some reason for that.
Forums attract similar minded people, never believe they are an accurate representation of the Real World out there.
Its just a 1x12
Not sure what speaker
Typical guitar speakers hit full distortion with very little voltage.
So not much power is needed.
To get louder you need more cone area
2x12 or 4x12
Same thing, once you have more cone area
not much power is needed.
Not sure why you wouldn't start with a Velleman K8060
Pretty basic Darlington amp.
If you were to design your own, you'd be starting with basically
the same simple circuits. And many 30 to 50 watt amps
made by manufactures use the basic topology.
Rectifier and caps are on the board.
You would just need a transformer with enough VA
for 30 to 40 watts. Which is all I would expect
from a pair of TIP142/147
Not sure what speaker
Typical guitar speakers hit full distortion with very little voltage.
So not much power is needed.
To get louder you need more cone area
2x12 or 4x12
Same thing, once you have more cone area
not much power is needed.
Not sure why you wouldn't start with a Velleman K8060
Pretty basic Darlington amp.
If you were to design your own, you'd be starting with basically
the same simple circuits. And many 30 to 50 watt amps
made by manufactures use the basic topology.
Rectifier and caps are on the board.
You would just need a transformer with enough VA
for 30 to 40 watts. Which is all I would expect
from a pair of TIP142/147
Not a bad price for a PT - but then again you have to buy another for heaters. 100 VA Anteks with a heater winding are $42. They will also support 12V tubes since it’s a dual 6.3V. 10CW5’s are also dirt cheap - just drop about 2V and you’re good. The 200‘s are more, but those were the ones I had, and if doing 2 channels it’s about right.
That amp is darn near the same thing, just self biased so a smidge less power, and with NFB. The CW5 is a more common tube, and they *look like EL 84’s. It’s just nice to have 70 mu triodes for free. We’ll, they cost you a compactron socket which you almost always have to go buy.
I ran it feedback-less to see if imbalance caused by 2H generation would upset the power toroid. The DC imbalance never got bad enough to be a problem. This is good news for using power toroids in high distortion amplifiers. Usually, in a hi-fi application feedback reduces 2H, and with it, the DC imbalance that accompanies it. In the end, you’d use some NFB, to taste.
Even if you choose different tubes, the topology is a formula that just works. About as simple as you get, if you want more than about 10 watts. Stay in the 300-ish B+ range and 50 Hz power toroids will work down to 80 Hz before they run out of magnetic headroom. Want to go above that, you’re stuck paying premium dinero. The ones George has for sale are a bargain - might want to take him up on it.
Of course there is always the option of solid state amplification. Cheaper for sure, but less forgiving when you start going above about 10 or 15 watts.
The preamps are supposed to add the desired distortion ahead of the power stage, yeah. But at war volume the power stages do add their own distortion. Properly done, that distortion is benign. Poorly done it sounds like a beehive or sawzall or even wood chipper. The trick with a 40 watt amplifier running on 70 V is to use a 200 or even 300 VA transformer and 10,000uf of cap. Don’t cheap out here. The amp will thank you when it’s driven hard, and go into overload gracefully. Yes, you’ll still see flat-topping, but you’d be surprised how much you see on the scope when it still sounds clean. I’d also advise something better than TIP142/7. Yeah, they work and don’t blow up (Most of the time). But the Sanken audio darlingtons make more well-behaved amplifiers. And a discrete EF3 (not 2) using MJ15003/4 better still.
