Can I do this?

[lgehrig4]

To be honest I'm still relatively new to this. I thought it was something that you were supposed to do with new amps.

I would really like to lower my B+ voltage though. It's currently 505V and I'd like to get it down to around 490V. I read something here about lowering B+ with Zener Diodes. What are your thoughts on this?

Why would my voltages be higher than normal anyway if the amp was built using the same component values?

I'll have yo check them again with the power tubes installed. The measurement was taken before tubes.

[ampdoc1]

I've never heard of burning in an amp in this manner. I'm sure it can't hurt, but I'd think a better way would be to put all the tubes in and use a Variac to slowly bring up the voltage.

And, i can't see much point in dropping your voltage 15 volts. That's a 3% difference that I'm pretty sure is not detectable by ear.

a'doc

[ampdoc1]

I've never heard of burning in an amp in this manner. I'm sure it can't hurt, but I'd think a better way would be to put all the tubes in and use a Variac to slowly bring up the voltage.

And, i can't see much point in dropping your voltage 15 volts. That's a 3% difference that I'm pretty sure is not detectable by ear.

a'doc

[ampdoc1]

I've never heard of burning in an amp in this manner. I'm sure it can't hurt, but I'd think a better way would be to put all the tubes in and use a Variac to slowly bring up the voltage.

And, i can't see much point in dropping your voltage 15 volts. That's a 3% difference that I'm pretty sure is not detectable by ear.

a'doc

[ampdoc1]

I've never heard of burning in an amp in this manner. I'm sure it can't hurt, but I'd think a better way would be to put all the tubes in and use a Variac to slowly bring up the voltage.

And, i can't see much point in dropping your voltage 15 volts. That's a 3% difference that I'm pretty sure is not detectable by ear.

a'doc

[lgehrig4]

I've never heard of burning in an amp in this manner. I'm sure it can't hurt, but I'd think a better way would be to put all the tubes in and use a Variac to slowly bring up the voltage.

And, i can't see much point in dropping your voltage 15 volts. That's a 3% difference that I'm pretty sure is not detectable by ear.

a'doc

I want to do it to save tubes. I already blew 2 pair and 2 fuses.

[lgehrig4]

After having a chance to hear the amp with the K60 preamp I want to change it to a complete Concorde. I've read what the differences are, but I don't know exactly what those changes mean and need a little help.

Please tell me if any of this

1. Remove 220k and replace with 330k that previously connected the 220k and 10k. This now goes to pin 2 of V2.

2. 10k resistor changed to 3.3k and now goes to pin 3 of V2.

3. Looks like the 100k resistor with .022uf cap now goes to pin 8. Is this correct.

4. I can't tell where the lead going to pin 5 is coming from since it's under the board.

5. What is the value of the resistor soldered directly to V2 and is it jumping pins 1/7?

6. Addition to the resistor on pin 1 there is a wire and I cannot tell where it's coming from.

7. After moving the 330k to the 220k spot is it still tied to the .1uf cap like the 220k was?

Any help with this would be appreciated.

[lgehrig4]

Ok, I need to tix something before I consider switching to Concorde specs. Something is wrong because it just keeps blowing power tubes.

Good news is I measure the voltages again and V4/5 are down to 487V and the B+ connections prom the power board are now 481V,452V and 429V. Preamp voltages on V1 & V3 are a bit high but I don't think that has anything to do with the power tubes blowing.

I put in another pair today and it sounded fine. After about 5 minutes I start hearing a tic similar to amps with tremolo, only the tic was deeper and slowly getting louder. There was a blue glow in the center of the tubes that was flashing to the beat of the tics.

I just turned the amp off before anything shorted this time. What do you think this could be? Where do I even start looking? If the voltages look good and the connections are correct, what could be causing this?

Thanks
Jeff