CCV Bias Setting

Equ1nox

Active member
Anyone know what MARK biases his CCV amps at?

Reading through the threads, I see some variation, but came across a thread where Brad King said Mark biases them hot and it's because he likes how the sound is biased hot. I will take that as a confirmation, but did not detail the setting.

I know you're supposed to bias the HIGH side primarily with the higher voltage on a HI/OFF/LO, but what is that setting?? I know with my other amp from Mark, the plate voltage is ~546V and the tubes show a bias of 51.0 and 52.0mA...but I have no idea if that was what "he" originally set. Any insite into this?
 
I found a link this morning (after the first 3.5hrs of sleep and before the next 1 hr and I went to work) in a thread back in ~2011 when Brad King was working with Mark and the question came up. Mark allegedly told him 40mA on the high and 38mA on the low!

I wonder what everyone else who owns CCVs have their set at or have additional insite into this. As it has been confirmed by others that Mark does bias as high as 50mA when certain tubes are used, I', thinking the other amp I have may be right, but I can check to ear and if best or no difference set back to the level it was at and check the resistive value before I start.

Anyway, if anyone has any additional information, please provide. Thanks.
 
Well, I'm not obsessing, just really asking for "owners" to chime in what they have their bias setting at and would like to know 100% what Mark biases this amp design at.

Looking through the threads from years ago, it is EVIDENT there i significant effects of tone on thie amp design and many folks chiming in at the time saying their amp was biased at 46, 48, 50mA and above!

A couple in particular are the following and I will measure mine when I get it, but would like to know what others have theirs at and recieved "stock".

Mon, May 24, 2010 8:50am
parntz145
Ref: viewtopic.php?f=25&t=69299&start=50
Hey guys,
I was talking to Mark about 2 weeks ago and we were talking about biasing the CCV. He told me to bias it at 38 on the low and 40 on the high. I just wonder why he is saying all these different ranges?

Sun, Oct 02, 2011 11:30am
King Guitar
Ref: viewtopic.php?f=25&t=102473
From Marks mouth directly:
"I set the Bias hot because it sounds best to me. I designed the amp to run a hot bias on high power and that contributes to the tone I like. I have had no problems with premature tube failure with the hotter settings"

"I wonder why CCV's are biased sooo high. Like 50ma or higher?"

"I will say though, when I first got mine, it was running around 46mA too. Mark must like to really run the bias high and get those tubes cooking, lucky Winged =C= are practically bulletproof!"

"Another factor where I'm concerned is I don't run in High all the time... In Low my amp runs @ 38ma, and that's where I stay mostly"

"34ma sounds like Drivel! and 55ma Is the sound of the Gods!! I think 44ma is a good comprimise."

RoidRage
"Mine cruises along @ 38ma in Low... I I play there unless I want to Reeek HAVOCK!!!"

steve_k
"So, if Mark says the CCV delivers 530 volts through the Mercury iron and suggests to you 38mA. He is actually saying that he feels comfortable with you running SED Winged C's at 80% dissipation. If Tony chooses to run his at 100% of the tube limits, that is about 48mA. Or, if Dave wants his at 70%, which is the common disclaimer for extending tube life, then he set his at 34 mA."

Erock
"If it's the same as the original run, the plate voltage was really high on mine, like in the 520+ VDC range."
 
Ok, got my CCV last night, but had very little time to play with it beyond checking all voltages and bias settings.

I'm looking forward to getting home after my 8 hours and spending some serious time with it and setting up the Roland RF-3 pedal.

These are the voltages I came up with using a variac to set the incoming voltage to 120VAC exactly and using a Bias-Rite dual head.

I checked plate voltages and bias and it's basically 516VDC on HI and 432VDC on LO. The bias on low was 34.7mA (V7) and 40.7mA (V8) which equates out to 60% and 70%, but the high was 60.5mA (V7) and 62.0mA (V8) meaning 125% and 128%!!!! There's no red-platting, but man this seems very very high.
 
Looks like the bias was set using low power? 62 is crazy high. I would lower it asap to reduce risk of tube failure and possible amp damage.

Also, those voltages seem a bit low. Typically the CCV's Mark has made are 550+ on high and 450+ on low. The lower voltages aren't a bad thing though. ;)
 
Yes, they do seem a bit low...usually circa 540V HI, 440V LO. Probably because the bias is set high.

My other completely hand-built by Mark in the Standel chassis I measured at 546VDC on the plates and 51.0mA and 52.0mA respectively. That would be ~111.4% and 113.5%. HIGH, but not as high as the CCV. Oh well, it's noted. I will lower it and by ear and also the settings noted above in other threads (40mA high, 38mA low) and see what sounds best. Now that I blueprinted it, I can always set it back...right? lol

I just crunched the numbers. If the bias numbers from Mark via parntz145 are correct and 40mA hi and 38mA low and voltages are 540V hi and 440V lo, it would be 86.4% HI and 66.9% LO which totally makes sense. We'll see.

Can't wait to get out of work and spend some time with it.
 
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