So here is what I have learned so far on the VTA board....
1. My low gain board purchased assembled from Roy did not work for me, trying it 4 different times in different amps.
2. I used a new power supply, a new quad cap, original A-470's(in two attempts), new A-470's twice (in two attempts)
3. 16ohm tap yielded oscillations as soon as bias began to rise every time
4. 8ohm tap worked for an extended period of time pushing my KG-4's, but a new power supply from Kevin burned out
5. 8ohm tap will still work and is stable pushing only two small surround speakers, single cones
6. 8ohm tap will not work on my Klipsch Heresey's at all
7. Suggestions made were to try varying resistor and caps for the NFB to tune it in
8. In each case an original circuit driver board works perfectly in every amp I have tried the VTA board in
9. A triode EF86 based board also works perfectly in every amp I have tried the VTA board in
10. The VTA board was not as spec'd according to the parts list Bob supplied in respect to caps on the board, which Roy acknowledges he sometimes makes some "changes" on assembled boards
11. Bob has been very helpful in trying to help me solve my problem, and if I buy a kit it will be from Bob or Kevin, not a question in my mind
12. Roy also has been very helpful, however did jump to some conclusions that the amps, not the board were the culprit, which one would expect of course
13. Roy has offered me another board, however with a fee applied to it, and only if my board can be resold, again understandable given the time it has taken me to get to this point
14. Roy would accept my amp to go over and charge me labor times at 40 to 50 dollars an hour depending on the problem, everyone needs to be paid for their time, it's only right
I have changed over the VTA board again to the Triode board, which is a great sounding board to me. The amp is running perfectly, all voltages are within specs, no problems with hum etc.
So my conclusion is the VTA board needs to be looked at for a problem within the board itself. I have to contend that their is some design flaw or component on the board that is causing me the issue with the type of speakers I use, e.g. Klipsh KG-4's or Klipsch Heresey's. Roy and Bob have a lot of these boards in the field performing well with many happy customers. Given the amount of time I have had the board, Roy's position is understandable in reference to switching the board for a fee or going over the amp himself and charging labor time.
I never tried to return the power supply to Kevin since it was a good 6 months before I got to the project and installed the board into an amp before the power supply went out. Kevin did offer to look into the problem himself however (I consider his service second to none), and I told him not to worry about it, I simply bought a new power supply from Heyboer that was built to the exact specs of the power supply Kevin sold me. Heyboer is right in the same town I live in and I thought any more problems would be easier handled locally rather then asking Kevin to deal with it. Thankfully all 4 of the power transformers I have purchased from Heyboer are performing perfectly and run cool all the time regardless of the tubes I have used or the boards I have tried.
So it was a great learning experience for me and I'm the type of person who doesn't get uptight about this sort of thing. If you're going to get into tube amps and change original parts to different circuitry you're going to have to learn a lot. I would use the VTA board again, but ONLY if I bought it as part of a kit from Bob. I wouldn't try to use the board as an add-on for an existing amp.
When the amp did work for a couple months and I was using with my KG-4's on the 8ohm tap it sounded very good. It was a different sound however then an original 7199 circuit board and also different from the EF86 Triode board. The sound was very clear and clean, almost to the point that it lost some of the "tube magic" if that makes sense LOL. At this point I prefer the Triode board myself, in my configuration of speakers.
I hope that Roy can use some of the information I gave him to help him in the future refine the low gain board for a wider application of speakers. Wasn't it Edison who said something like "I never discovered how to make a light bulb, I did discover several hundred ways you cannot make a light bulb however" LOL. Something like that anyway. Trial and error is the only real way that anything can be developed and it will always take some time and some failures to do so. We learn from each failure we make and it adds a bit more knowledge to the task, allowing for eventual total success. I am going to order some parts and experiment with the board as Roy suggested, this will further my understanding of the circuits involved and the interactions taking place. That can only be a good thing.
This has been a lot of fun guys, thanks to everyone.