| Author | Message | ||
| Christophe Le Crom (vignau) Username: vignau Registered: 08-2010 |
Hi, On my 210HD130 (2275 EX 130) all is alright , amps sounds awesome, all caps job done and tubes/bias, BUT reverb does not sounds good ; it as never sound good to my ear (I got this amp in 1979) compared to a twin reverb, as much as I remember in my ear 30 years ago � I have the chance to have this musicman still now and a twin reverb (silverface ,1975) for comparison and my ears says reverb is two short on both �. They have both the same short reverb sound�, too short, nothing to do with my pedal BOSS RV3, digital, in which I identify the sound I remember on silverface twin,. I am sure I could find back this sound. Might be linked with the higher voltage service (see my just recent post on high B+ voltage on export amps). I have the good accutronics reverb tank: (4FB3A1B) for my musicman, (4AB3C1B) for my �75 twin. I have already read from Mike Kaus that tank weathered� Technically, Mike, how can you explain that ? it�s just springs and transformers� Anyone can have a better explanation (voltage service, dead or semi dead component ?). Thanks for feedback, especially from EX owners� AND, thanks again to Steve, Mike, Lars and others good guys, for this awesome forum, sounds as a musicman !!!! | ||
| Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008 |
I guess the job is to make sure its the tank thats bad or weak,it could be other things but most likely its the tank,there are many great replacements out there,and many pedals that are really exceptional these days . | ||
| Christophe Le Crom (vignau) Username: vignau Registered: 08-2010 |
Thank's Bill, again, it has never sound good to me even when the amp was brand new. Should I keep think its a tank problem ? ref is 4FB3A1B; another ref would work better ? | ||
| Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008 |
http://www.tubesandmore.com/ this is a site that has the acutronic tanks might help.might check to see what kind of voltage you are putting into that tank as well. | ||
| Christophe Le Crom (vignau) Username: vignau Registered: 08-2010 |
Thank's Bill, the technical description on tanks is very good on this site, but there is no reference voltage displayed. What voltage should I consider as reference? Thank's again | ||
| Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008 |
you should only have voltages on the + and - supply pins, around + and - 15 to 18vdc. There should be little or no voltage on any of the input or output pins. | ||
| Christophe Le Crom (vignau) Username: vignau Registered: 08-2010 |
Bill, just measured: both impedance on the tank (input/output) are 180 ohm. little or no voltage on any of the input or output pins, what you mean by + and - supply pins, around + and - 15 to 18vdc ? Where to measure that ? Cheers | ||
| Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008 |
the input pins should have around that voltage,if they don't then you gotta trace it back more . | ||
| Christophe Le Crom (vignau) Username: vignau Registered: 08-2010 |
OK Bill, thanks, I will do that; so almost no votage on input/output would make the reverb working (even with a short delay ? ie my case) Maybe a LM307H ? When looking at the schematic, it seems strange for me to have that kind od 15-18 vdc, why should we have there such voltage direct current ? regards, Chris | ||
| Bill Traylor (bozzy369) Username: bozzy369 Registered: 02-2008 |
yeah it could be the op-amp,something burnt along the way cutting down the power ,bad pot?and there are a whole lot of things dc in these amps ,but alot of other amps run alot of dc in them too. it's just easier I guess,hot and ground. | ||
| Christophe Le Crom (vignau) Username: vignau Registered: 08-2010 |
Bill, I will swap an OP from channel 2 for tests. Anybody have vdc measurements around the reverb circuit? I just want to get this 210HD back to original, I have external solutions for good reverb�.BUT a good reverb on that amp would simplify things, just for a direct plugging !!!! |
Tue, 03/25/2014 - 09:35
#1