I have tried the board in a pair of Heathkit W-7's. I bought two of them and didn't use the third 12AT7 of each board because the W7's are monoblocks. Also, when stuffung the boards only use pins 1,2, and 3 of the middle tube and all the parts associated with them because the input circuit shares both halves of the middle 12AT for the input of each channel on a Dynaco or any stereo amp. I also didn't use the bias supply on the board. I used the stock bias supply from the original Heathkit circuit. I put the board on standoffs and built a small wood sub chassis around the board for looks. It looks unusual but it looks good in my opinion. I didn't put any parts on the bottom of the board as described in the original picture on the VTA website. I was able to get the board down a bit lower to the chassis. If the new bias supply built on the board is used then you must put the bigger coupling caps on the bottom so you have access to all the bias pots when needed. That means you will need taller standoffs.
Now for the sound. Let's just say I used the board on a few Dynaco's and I was happy with the results as compared to other mod boards and stock boards I tried. But when I put the boards on the Heathkits it took on a new life form. Dynamics in spades. Musical? None better! This is the best mod to an EL-34 amp I ever heard. The music is about as real as it gets with lifelike images that make you feel the musicians and singers are in the room for a personal perfomance just for the listener. The bass is extremely accurate and tight on the Heathkits. I felt it was a bit bloated on the Dynaco. Using a different feedback resistor and capacitor value helped but not like the Heathkits.
Try this board! You will be glad you did and it is easy to install.
Now for the sound. Let's just say I used the board on a few Dynaco's and I was happy with the results as compared to other mod boards and stock boards I tried. But when I put the boards on the Heathkits it took on a new life form. Dynamics in spades. Musical? None better! This is the best mod to an EL-34 amp I ever heard. The music is about as real as it gets with lifelike images that make you feel the musicians and singers are in the room for a personal perfomance just for the listener. The bass is extremely accurate and tight on the Heathkits. I felt it was a bit bloated on the Dynaco. Using a different feedback resistor and capacitor value helped but not like the Heathkits.
Try this board! You will be glad you did and it is easy to install.