Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

schem or info on Pearl (japanese) amp

3/23/2006 7:13 AM
JC schem or info on Pearl (japanese) amp
I've got a Pearl (Musical Instruments Co., made in Japan) instrument amplifier for repair, made I guess in the mid to late 70s.  
It could be a bass amp, but I'm not completely sure about this because the lettering on the faceplate is quite dimmed and 'model bas ???' is all that can be read. It is a ss combo with reverb and vibrato, and bass and treble boost switches. And a brilliance control.  
It is now working but the reverb and vibrato are not added to the signal, although they are working, because I can hear the vibrato 'beat' and if I knock the reverb pan there is a... reverb pan noise.  
I would need a schem.  
I had no success about Pearl amps with Google.  
Any help please?  
3/23/2006 9:54 AM
JC D317A is it a voltage regulator?
Does someone have the data for this component please?  
I believe it could be a voltage regulator of some sort, same package as the 7918 / 7818 regulators  
For the moment I haven't found the schem for this amp, and I am guessing it is a '+' regulator.  
Book Of The Day The Ultimate Tone, Volume III by Kevin O'Connor
Have you ever wondered if there is a better way to build a Bassman, Champ, Plexi, an 800, AC-30, Bulldog or Portaflex? Or you wanted to build an SVT with off-the-shelf parts? How about a master-volume amp that doesn’t change tone with the master setting? Everything you need to know is right here, including: proper grounding techniques, wiring methods, and mechanical considerations. Eighteen chapters cover the “iconic” amps everyone knows and loves, with schematics and layouts for each, along with the technical history of the product. Eyelet-board and chassis-mounted tube socket construction is used throughout, for easy servicing and modding. TUT3 is very accessible even if you cannot fully read a schematic and is a "must have" if you are going to build an amp for your self.

Note: The Ampage Archive is an Amazon Associate site. A small commission is paid to the site owner on any qualified purchase made after clicking an associate link such as the one above.
3/23/2006 1:04 PM
Dai H.

maybe a 2SD317A?  
sorry I don't know anything about the amp.
3/23/2006 2:51 PM
Yes it could very well be one of those. I will try to find a replacement.  
Thanks a lot, Dai.  
3/23/2006 8:10 PM
Re: schem or info on Pearl (japanese) amp
If it has reverb, it is not likely a bass amp.  
Is ther a footswitch jack? The effects may need a FS to enable them.  
That the reverb makes noise if you swat it tells us the pan output works and the recovery circuit in the amp, but that says nothing of the reverb drive circuit. Make sure the pan is not open at either end. Follow the wiring and traces back from the INPUT jack of the pan to find the chip that drives hte reverb pan.
3/25/2006 4:35 PM
Dai, Enzo,  
I believe I've got it working now.  
Funny little amp. It had faults in the power section, the reverb, the vibrato and the tone boost controls, and the speaker had a couple of rips.  
The only working part of the circuit was the brilliance control. :D  
The reverb and vibrato is always on, the footswith mutes them connecting them to ground.
3/26/2006 12:48 AM
Dai H.

that's cool. just finished working on a mini hard drive (which had a broken pin from my brother trying to force the connector on backwards) which I had managed to salvage by connecting a wire to the stub, breaking open the plastic part of the connector/adaptor and soldering to the pad inside there. Seems to have been a little tiny space from the solder joint getting in the way of being able to press down the connector all the way, and it was going intermittent. Anyway I cut away some of the plastic to get a more solid fit (seriously straining my eyes). Seems to be working now I HOPE. I'll cross my fingers for your amp and my hard drive, lol...
   Page 1 of 2 Next> Last Page>>