About a year ago I asked a question of forum members. "What would you like to see in an amp for your studio".
 
I didn't get a single response so I just moved on. Well, I've been thinking about it and have designed and built a new amp for both a home and professional studio. The amp is a fairly simple single output tube design, 100% hand wired with the best parts I could find. It will use almost any 8 pin pentode or beam power tube. Anything from a 6V6 to a KT88. THe pre-amp features a 3 band EQ and an EF86 front end. 
 
What makes this amp different is that it doesn't sound like a small amp. It is REALLY quiet and uses transformers with a broader frequency response than most guitar amps. This allows you to run guitar, bass or keyboard through the amp with excellent fidelity.
I won't go on much more for now since the entire project is being published online as a 3 part article. The first part is up now and the next will follow in a few weeks. I don't give exact instructions on how to build the amp for reasons of personal liability, but I will be providing enough information for you to do so if you have some experience.
 
Here's a link to part 1.  http://blog.thetubestore.com/if-you-cant-find-it-build-it-diy-amp-part-one/

Looks nice John.

i think if i was starting up a 'studio for hire', i'd go with a Kemper Profiling amp.
 
of course,
having a stable of basics (Fender Vibrolux, Marshall JMP, Vox AC30) would cover 95% of everything.
 
but having a custom built amp,
is what i called 'dialed in'

Way cool John! I wish I had the electronics chops for projects like that.
 
Rocky

Thanks for sharing that John! I was just thinking about how much I'd like to try out a 65Amps Ventura which also has an EF86 and 6V6's, if memory serves.
Michael

 

From Part One :
 
5. In order to provide tonal options I need to run a variety of output tubes without any adjustment
...
In order to change tubes on the fly I had to go with a cathode biased design.

 
 
I have had little time to play with my own tube amp, let alone try out different tubes.  Definitely something I want to get to in the not too distant future.
 
I'm curious, John, just how obvious are the sonic differences between tube types ?  I like your idea of this amp serving as a base into which you plug different tubes for different effect.  Can you give us an idea of what kind of changes you can get ?  Are they only noticeable to an experience guitarist or are they obvious ?  In what respect - tone (EQ), distortion, dynamics, (something else ?) does the behaviour of the amp change ?
 
Are you confident that the circuit layout, voltages and component values are (will be) good/ideal for all output tube types you want to try ?  Are the tube types really that compatible ?

There is a difference between tubes that's hard not to notice and the design is such, that you can reliably switch between them. Most of your questions will be answered in the articles, so I suggest you read them if you're interested.

To answer a year late, I'd say: An amp that makes -0- noise (no fans - no hums) and delivers clean sound at all frequencies at an affordable price. ...
 
But I want too much.

That's a really cool looking design. I might just have to give this a try... I will be waiting (patiently of course) for your approach to a switch-able output tube design. I've tried in the past, but never been happy with the compromises I had to make.
 
Very nice of you to share the fruits of your labors!!! I hope to return the favor.

Looks great.  Too bad I have no time or training for such.  I would like an amp (and cab) of all trades for here at the house for synths and when the odd guitarist stops by (and I wouldn't use any thing but an odd one!).  Thanks for sharing.
 
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