| Author | Message | ||
| Rick Viola (goodrat) Username: goodrat Registered: 05-2011 |
11-15-11 RJV Current rev is E -Parallel 2uF/350v across C35 (2uF) for 4uF total -Changed C33 and C34 (60uF) to 100uF -Changed R9 (560K) to 100K , leave R10 at 100K. -Changed R12 (5.1K) to 1.82K -Changed R11 (330K) to 200K -Changed R69 (3.3K) to 1.82K -Changed R61 (47K) to 15K -Parallel 47pF across R21 (82K) -Add 150K in series with V2-7 grid -Note: C48 and C10 are 10uF. -Changed IC1 to OPA2604 | ||
| Rick Viola (goodrat) Username: goodrat Registered: 05-2011 |
Sorry double post. I thought the post didn't work due to how far down the list it was. But this is current. I had a problem with the 12AX7 being microphonic, but a new Electro Harmonix 12AX7EH cleared that up just fine. Current measurements (I think): C34 283VDC C33 565VDC C35 263VDC, Ripple = 200mV p-p ? C6 200VDC (63V across R9 = .63mA idle, -1.14vgrid) PLATE 12AX7 141VDC | ||
| Rick Viola (goodrat) Username: goodrat Registered: 05-2011 |
Correction, the plate is 130V and 67V across R9, so idle current is 0.67mA and grid is -1.22. All other measurements the same. I must have measured with the 180K Plate resistor. I think I will leave it this way. Although I wonder about lowering C48 and C10 cathode caps. They were there from previous owner at 10uF. The dist channel is like the normal until the dist gain is > 3. |
Tue, 03/25/2014 - 09:35
#1