I know, i know it is not a tube amp, it is 1967 Vox Cambridge reverb V1032 solid state amp. It is very vintage and cool looking though ). Originally it just had 60hz hummm. I replaced all filtering capasitors and the amp came to life! However, every note I play on my strat, i hear a ghost note, that is the same low pitch, about 120 hz... Does anyone know what might cause this ghost note? I read something about it some time ago but I can not remember... the main capasitor was 5000 uf, but all I could find was 4700 uf, could that be the reason?
Thank you.
PS i am attaching the schematic, just in case”
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I'm not 100% sure, it 'could' be that you're under filtered, but it could also be that any one of the new filter caps didn't get a good solder joint either on the + or ground connection. I do think that's a sign of not quite enough filtering, or 'caps going bad' but you just put new ones in.
pompeiisneaks wrote: ↑Sat May 05, 2018 2:58 pm
I'm not 100% sure, it 'could' be that you're under filtered, but it could also be that any one of the new filter caps didn't get a good solder joint either on the + or ground connection. I do think that's a sign of not quite enough filtering, or 'caps going bad' but you just put new ones in.
~Phil
Thank you, Phil, for your help. Yes, after I replaced the 4700 uf cap with 5700 uf cap ( the only closest to 5000 uf I could find at my local electronics store), the ghost note is gone or almost gone. may be I just hear some in my head. I mean, other filter caps suppose to be 500 uf and all I could find was 470 uf... Almost not a big dial, but I am thinking now to go with 570 uf value, just to be on the safe side... Working on the solid state amps is challenging but it teaches me new things and I like it... I know, that there is a ton of things I still need to learn about the tube amps, but there are huge similarities between transistors and tubes...
Quick question, the board on this amp still has like 6 smaller electrolytic caps (the black ones with the red end caps). I know their values has drifted some, but they seem to be working... Should I replace them as well, or if it is not broke do not fix it, kind of thing?
chikov wrote: ↑Sun May 06, 2018 4:46 am
Quick question, the board on this amp still has like 6 smaller electrolytic caps (the black ones with the red end caps). I know their values has drifted some, but they seem to be working... Should I replace them as well, or if it is not broke do not fix it, kind of thing?
Yes, you should ditch those and replace if you want the amp to work right and last for a while longer. See my post on the Vox Berkeley III I was just messing with a couple of days back. If you want a 1uF dual positive cap and don't have one, and why would you really, you can use two 2uF caps and tie together the negative ends to get a 1uF dual positive.
Just because you bought and installed new filters, does not mean that they where good!
Ask me how I know this!
120 hz hum and or ghost notes are fully related to the D.C. Side of the power supply and if your new filters are really good and your just hearing Ghost notes when playing loud then that may be normal when your pulling down the power supply voltage , this amps PTs do not have much spare current for solid peak wattage!
Your comment on the new filters taking care of a 60 hz hum issue makes no sense to me!
In your reworking of installing the new filters you may have inadvertently to your benefit moves some of the PTs primary or secondary wires where they effect the preamp circuit less!
These amps even brand new have some 60 hz hum whenever you turn up the reverb due to the physical relationship of the pan to the PT and AC wires in the amp.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
). Originally it just had 60hz hummm. I replaced all filtering capasitors and the amp came to life! However, every note I play on my strat, i hear a ghost note, that is the same low pitch, about 120 hz... Does anyone know what might cause this ghost note? I read something about it some time ago but I can not remember... the main capasitor was 5000 uf, but all I could find was 4700 uf, could that be the reason?
