Amp Builder Wanted

[Guitar Coach]

I am looking for an experienced amp builder to take on a custom build project. The amp that I have in mind is single channel class A head.

1. 3 knob tone stack (bass, mid, treb)
2. 5-8 watt el84
3. 1 input
4. power and stand by toggle switch
5. fuse
6. speaker outs

I have a schematic that you can work from but I'm sure it might need some tweeking. My budget is around $1250, I can be somewhat flexible on this. Please let me know if i need to provide any more info. Thank you in advanced.

[Bruce / Mission Amps]

You aren't going to get 8 watts from a single EL84 in class A. Possibly closer to 4 - 5 watts using killer transformers and the correct B+ level with a preamp that doesn't kill the grid of the EL84.
However, there has to be many guys here who would jump at this project at that price range!
It sounds like a simple single channel amp....
A head huh?
Send a schematic out and I'll (and others) will check it out for you.

[Guitar Coach]

Thanks for your response. 4-5 watts is probably loud enough for most places that I play and also be able to be heard over an aggressive drummer close knit jam sessions. Some of the rest of what you talked about is "greek" to me.

I will send you the schematic. It is the layout of the new Marshall Class 5 amps. I do like the tone they can get but have read that they can have some problems with durability otherwise I would get one of those and save some money. I figured to use this as a base or borrow from some of the ideas from PX-1 builds over at ax84.com (maybe even just order a kit and start from there).

I am hoping to get something similar with a greater degree of touch sensitivity and durability by having it custom built. I can also have it tweaked to my tastes a lot easier.

I am hoping that my budget is sufficient. Its not so much the parts that concerns me (they're not that expensive) but finding the right person and adequately compensating them for their time and expertise.

I would like a head so I can run it through a either a 2x12 or 4x12 depending on the situation. Also a lot of places I play have back line cabinets so all I would have to do is bring the head.

[diagrammatiks]

are you sure this is what you want? an el34 class A is not going to have much headroom at all.

It'll pretty much be crunchy from the get go.

[Bruce / Mission Amps]

to> diagrammatiks. It's an EL84 not EL34... which is worse as far as "easy" crunch goes, ha ha.
But the circuit does have some room for signal reduction and gain limiting.
Looks like a pretty easy build to me.. and your $1250 budget seem like quite a bit too much money to pay for something like this.

[diagrammatiks]

Ah I had misread and thought the op wanted a single el34.

the el84 would easier with a lower voltage transformer.

[big_teee]

Not trying to beat anyone out of a job, but why not build up a kit like everyone else does around here.
If you want a el84 Head I would build up the Marshall 18w head from TubeDepot.
It's $650 with a fancy Case, with a plain, and a Tremelo Channel!
http://tubedepot.com/kit-british18whead.html
Just my .02c.
Terry

[Guitar Coach]

I have thought about building a kit. Perhaps one day I will take it on but I lack the time, space and expertise to take on a project like that right now.

[Guitar Coach]

Yeah, I'm not looking for much headroom. I looking the amp to break up a lower volumes

[Mandopicker]

With the right transformers, could an amp be made using 2 x El-84's in parallel for 8 watts or so, Class A? That seems like an interesting build to me.

Maybe use a 125DSE or 125ESE for the OT.

[ChrisA]

I just built an amp like that. It's a single EL84, TMB tone stack. I used pretty good transformers over sized by a factor of two. It is in a finger jointed pine combo cabinet but I used a smaller speaker and have ans output jack so I can use it as a head. This way I have a portable practice amp but I plug in th bigger speakers for better sound the little built-in 6" speaker.

When clean it sounds like a Fender, I did this on purpose by adjusting some caps until I got that kind of clean sound. If that is your goal best to use a 6V6 tube or even 6L6. When you turn up the gainn it sounds crunchy. It will not go up to something a metal band would want but I did not want that. I typically use it right on the edge of clean/crunch and use a pedal.

As for how loud? With a 1 x 12 Emanance "legend" I can be heard inside the house next door. But it is not ear splitting as some big amps can be. It depends on the genre of music. A single EL84 does not have a huge amont of 'clean volume but many kinds of music don't need that. And you might like the fact that it breaks up at only moderate volume

This cost me about $250 to build. So yes if you give me $1,200 I'd be happy to pick up $950 for a few day's work. But if I were building this for some one else I'd outsource some of the work and it would cost me closer to $400. $800 profit sounds like a lot but $50/hour is not an unreasonable bench rate. That is an expensive way to buy a small amp but for custom built, no on will work for $10/hr.

A cheaper way to get the same thing is to buy a used amp. Even if you'd have to modify it. I might sell mine if the sale would fund parts for a second build

[soundmasterg]

For what you have in mind Guitar Coach, it sounds a lot like an Epiphone Valve Junior. A single EL84 and a single 12AX7. There are a million mods out there for them, and a stock one is like $129 new (if they still sell them.) If they aren't made anymore, then you can get one off ebay or other places. No need to spend $1250 for a custom amp of that nature. I don't see how one of those can keep up with a drummer either honestly. A pair of El84's or 6V6's would keep up with a quiet drummer, and still have enough there to open it up if needed.

Greg

[JoeM]

Another similar amp to the Epi Valve Jr., is the Blackheart BH5H, has TMB tone controls. A lot cheaper than $1,250.00

[GregS]

I thought that durability and reliability were important criteria here which was the reason for wanting something custom hand built.

[ChrisA]

I don't know about the Epi Valve Jr. I've not peaked inside one. But other small amps that it competes with it seem to be well-enough made. They might need an upgraded transformer and some component values swapped BUt that is cheap to do. Also, a guy with a $1,200 budget can afford to buy a spare amp and a good shipping case.

The thing abut hand built amps is (1) the amount if skilled labor involved, makes even a very simple amp expensive and (2) Parts are expensive when you only buy one or two of each. For example Fender can sell a Champ 600 for $149 retail but I could not buy the parts for that price and then hand building it would take a week.