How does it sound? Wellll... download an MP3 and hear for yourself! This a great amp for blues players with plenty of crunch at lower volumes.
Dr WOW played the amp for me, during an an un-practiced, impromptu performance, but does illustrate the sound of this amp.
I cut the first recording up into sections, but. Web space prevents me from posting them all.
section1.mp3 330k section3.mp3 411k section05a.mp3 380k section10.mp3. 595k
Guitar - 59 Strat Alder body, Lace Sensor Gold pickups.
Amp settings - volume dimed, tones centered. Volume turned down to half starting at section 8. (Guitar not shown.)
Mics - 2 x SM82 Shure condensors, 18v battery phantom, about 1 foot and 1.5 feet in front of amp, aimed off center, recorded stereo. Listen to 1 channel at a time if you like.
Recorder - Flint direct phantom box, PC Yamaha card, Cool Edit. No effects.
SPL - measured on B&K 2205 meter, slow setting, A weighted - 100 db/1meter. up to section 7, then about 85 db.
All recordings use absolutely no effects, other then the compression of the SM82 mic preamps, which prevent overload at high SPLs. They have built in limiters, and they are probably enabled at this volume.
NEW1TRK4mf.MP3 516k Danelectro, neck pickup, tone up. Amp; vol (10), tones (5). old speaker.
For a complete song, including bass, drums, and synth, check out July_Multitrack and hear how the amp sounds in a band...
I determined that the original amp #1 was a bit small - only a few speaker types would fit in it, so this prototype is bigger. Also, there was a lack of headroom with the 1 watt design, so I changed to above 3 watts rather then below... on the advice of Drwow...
BTW - this amp is quiet as far as hum and noise is concerned. If someone wanted to track with this amp in the studio, that would be no problem. With the volume and even tone controls turned up full on the amp - there is no audible hum! With hum-bucking pickups, they could expect a very clear session.
The main difference in the circuit is the addition of an active mid range control. I've noticed that the mid controls on most of the 'classic' amps don't work very well, they have poor range and limited action. This mid really works, and can boost or scoop the mids to unheard of levels compared to the classics!
One of the other issues I wanted to address was the problem of having the amp hidden inside a box, where the tubes were hard to get at, and the heat was cooking all of the capacitors! My unique design here addresses these problems and more - the tubes remain upright in the amp, and the heat is dissipated out the back of the cabinet, rather then frying all of the componants.
The circuit shielding is far superior, with separate sections for different circuits, and the tubes are isolated a bit more from acoustic vibrations in the cabinet.
This chassis is made up of separate boxes; I will be fabricating a custom one-piece chassis in future amplifiers.
It is designed to be used cranked up, producing relatively low volume, in either a bedroom practice enviornment, or in a studio. It could also be gigged thru a PA.
There is a 'high gain pot' as well as the volume control. This can be left turned down for the normal sound, or turned up 'till you like the crunch!
It is an intended low power low voltage design. The output power averages about 3 watts... so I imagine a cranked guitar can output maybe 5 watts in total. Is that loud? Well, the 100 dbSPL it produces is certainly loud for a house, and can even be giged!! And of course it can be PA'd as well. I tried jamming along with it with my 200 watt Vdrums, and I wished I had my acoustics!!! I know I know - you DREAM about drummers saying that! But at the same time, it doesn't produce the ear-splitting volume of your main guitar amp cranked full. 5 watts is not 100 watts!
This is a prototype, the chassis and layout is point to point - it works quietly, at least better tnan 60db s/n. The amps have star type grounding. The layout is designed for low noise. Also, SS diode rectifiers were used instead of tube rectifiers for 2 reasons - 1, because it is class A, the current never changes, so 'sag' is not an issue. (Some people think that because the tube manual lists min and max current for class A circuits, that means sag, but actually, it means that a waveform going thru the amp has a max and min current, but the average remains constant.) And 2, I can use a lot of filter capacitance, EG 350uf in total, so that there is absolutly NO HUM!
Price? Well, I hope to be able to deliver them from $US 600 to $1200, depending on options like speaker and extra controls or jacks or whatever. The first series of prototypes will be sold for whatever! Demand will determine if I go into production, or just assemble the odd one now and then. I also plan on a P-P higher power design, but mostly to change the tone, not to break eardrums... also a rack version is possible, I have lots of surplus rack chassis, saves money...
The various blocks will range in price and in quality. For example, an old 50s Fender-type tone stack is the cheapest, and probably the worst 'quality'. An Ampeg type filter control, on the other hand, is the utmost in features and complexity. Its quality and effects are superb, but so is its price! 5 tubes for a tone control, neat!!
Now - some people insist on tube rectifiers for the so called 'sag' they get... however, analysis of over-loaded tube supplies shows that what really happens, is that the AC HUM componant of the voltage increases... because the cap isn't being charged, since all the power is going to the power amp tubes. This is like running your amp without a cap... imagine the HUM!! But the 'sag' effect is really a matter of compresion, and I'd rather have a compressor do it!
This of course doesn't apply to class A amps like mine. I have elected to use a good silicon diode pair, since I would rather have large capacity and no hum. Right now, I'm using 350 MFD of capacitance. Compare that to those old 20/20/20 cap supplies used with tube rectifiers.