• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Reading material


2009-03-11 2:15 pm
Hi all,

Im shortly going to be starting an MPhil research degree on valve microphone preamp design, and am looking for some more reading material.

So far I have,

Both the Morgan Jones books
The tube preamp cookbook - Allen Wright
Small signal circuit design - Douglas Self

Does anyone have an ideas that would help my research?

Thanks in advance

It would come under audio technology, my university has recently opened a research department and are keen for me to work with them.

The proposal is still in its early stages, but my main aim is to design a very quite great sounding preamp. There's also a lot of interest in modeling, that could also be a topic of the M.phil.

Its obviously not a novel study, companies have and are designing such preamps, but for me its about creating the perfect working conditions for the valves through extensive trials and test, and to hopefully have my own product at the end.
I'm not convinced that there is such a thing as "perfect working conditions" for a valve; they age, and start with wide spreads anyway. If it is not novel, how come it qualifies for an MPhil? I thought an MPhil had to be original research, but shorter and less creative than a PhD.

Anyway, I hope it goes well. Don't forget to mention us in the thesis.
It doesnt have to be completely original, thats how we are doing it. Its going to be an interesting 3 years, I have a lot to learn but also I think Ill come up with some original ideas.

Ill certainly be coming back to you guys for help, so thank you for putting up with me in advance.


M Gregg

Disabled Account
2010-06-28 11:04 pm

"Perfect working conditions" for a valve.

This would only be possible if the circuit had "closed loop" control. This would have to control "all" parameters at all times.

Perhaps micro controller monitor and feedback. However are you trying to create new applications, or new variations on known circuit design?

I would have thought that most topologies have been tried through the years so you are going to have to come up with something quite radical. OTL, PP, PPP, SET, hybrid have all been done. Marshall had valve state and many mixer and preamp types.

Perhaps you should research recording studio designs through the years that would give professional ideas and applied circuit types.:)

Try reading The tube Amp Book Aspen Pittman. O.K. It's Groove tubes. However it will give you a "Feel" for your project!

M. Gregg
Last edited:
Thanks M Gregg,

Id have to say it would be variations on know circuit designs, as this technology has been around for a long time, and no doubt its 'all been done before'.

Like I said the proposal hasnt been finalised, at the moment im gathering information and ideas.

I guess the reasoning is that although many companies have done this before, I want to come to my own conclusions and really, I want to develop my own circuit for what I feel is the right sound. Im not sure that makes sense......

I think it will be interesting, having the ability and time to vary all parts of a preamp design im hoping some original ideas will come out of it.


M Gregg

Disabled Account
2010-06-28 11:04 pm

You have alot of different battles to fight with this project. High voltage and noise. Heater high current more noise. The millions of different combinations of component types and their sonic signature. The cost! The problem that limitation of frequency response will effect the quality, linked to circuit saturation. "Output swing and noise creating clipping".

M. Gregg