|
|||||||
| Home | Forums | Rules | Articles | Store | Gallery | Blogs | Register | Donations | FAQ | Calendar | Search | Today's Posts | Mark Forums Read | Search |
| Instruments and Amps Everything that makes music, Especially including instrument amps. |
|
|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving |
![]() |
|
|
Thread Tools | Search this Thread |
|
|
#1 |
|
diyAudio Member
Join Date: Nov 2012
|
I recently acquired a position repairing amplifiers for a music shop in Massachusetts on a sub-contract basis. I was given a Dean Markley RM-80-DR to troubleshoot a matter of weakened volume on the top channel.
I have looked everywhere for this schematic. I even asked the manufacturer. Does anyone have it that would be willing to email it to me or better yet post it? Also, has anyone else experienced this issue? If so, how did you solve it? Maybe this amp's circuit is the same as another similar model that I could find? Please help...thanks, Twombstone |
|
|
|
#2 |
|
diyAudio Member
Join Date: Sep 2004
Location: Lansing, Michigan
|
This DIY board is a fine forum, but if you are going to be doing amp repair, I think you need to visit a few more that are more focused on instrument amps rather than hifi.
Try this one for general coverage, and note they have a schematics request section on the menu. Post your needs there. Music Electronics Forum A smaller board that concentrates on solid state: Solid State Guitar Amp Forum | DIY Guitar Amplifiers - Index If I have that schematic I'll post it. I'll have to look. |
|
|
|
#3 |
|
diyAudio Member
Join Date: Dec 2011
Location: North-East England
|
The pic attached has been posted on here in relation to a previous query. It's only a fragment, but something to start looking at.
Sometimes fate smiles after all ........ I have to say that, after putting a scope probe across the tremolo neon in a twin reverb showed me exactly the snubber circuit to use to stop it clicking audibly....about 30 secs after starting work. Good luck
__________________
Engineer: One who can do for 10 shillings what any fool can do for 10 pounds. |
|
|
|
#4 |
|
diyAudio Member
Join Date: Apr 2010
|
Clean the controls.
Then check the J-FETs that are used for channel switching. Next likely would be cold solder joints. Be careful, the pads will lift off of this board if too much heat is applied. If you've downloaded that schematic link that was posted on ME forum, you will see that most parts of the amp are common, including the tube. |
|
![]() |
| Thread Tools | Search this Thread |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Dean Markley T120-R fixer-upper project. | mondogenerator | Instruments and Amps | 28 | 11th September 2012 05:28 AM |
| dean markley valve head 120 watt | mondogenerator | Instruments and Amps | 19 | 25th February 2012 06:09 PM |
| Dean markley DR-80 Pre Need help | screamersusa | Instruments and Amps | 1 | 11th February 2009 08:16 PM |
| Nakamichi Dragon+RM-580R Remote | steve_pan | Solid State | 5 | 5th October 2007 08:35 AM |
| Calling Dr. Fletcher! Dr. Munson! Apparent 20 dB Discrepancy! | kelticwizard | Multi-Way | 10 | 18th November 2004 01:59 PM |
| New To Site? | Need Help? |