Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: bob_amos on May 04, 2009, 08:57:48 PM

Title: Frontman 212R help needed
Post by: bob_amos on May 04, 2009, 08:57:48 PM
Hi everyone. I just purchased a Frontman 212R that has a problem with the gain. The amp is loud enough to hear while practicing but when I turn her up the volume stays as it was. No increase. What I really would like is a schematic for the Frontman 212R. I have the FM 212R but it does not appear ro be the same. Any help on a schematic or where to look would be appreciated.
Title: Re: Frontman 212R help needed
Post by: Enzo on May 04, 2009, 10:38:40 PM
Did you buy it new?  If so, it is under warranty, and they will replace it.

If you did not buy it new, what is different about your amp compared to the FM212R.  As far as I knew, they were the same amp.  FM = Front Man.
Title: Re: Frontman 212R help needed
Post by: bob_amos on May 04, 2009, 10:51:32 PM
It's not a new amp, it is actually a Fender warrantee return. The FM and Frontman are different amps. The FM is a cheaper version. The circuitry is different. I have a number of Fender amps and all of my FM series amps are assembled much cheaper. The pots have no nuts holding them to the chassic as they just stay in place from the legs that are soldered to the board. My schematic for the FM 212R does not match my Frontman 212R amp. I was confused by that too but owning a few of each has educated me on that.
Title: Re: Frontman 212R help needed
Post by: J M Fahey on May 05, 2009, 04:28:54 AM
Hi Bob.
In that case, take the shortest path: ask Fender themselves. Be sure to include model and serial number in your mail and they´ll very probably mail you back the schematic.
At worst they might ask 5 U$S for it.
"floating" pots are a pest in guitar amps (and everywhere else)
*If* you get it, please post it in the schematics section so we can see what difference, if any, exists between it and the FM.
Personally I think they should be the same or almost.
Saving U$S usually means things like what you saw, saving assembly time and such, rather than messing with the schematic itself.
In particular, Fender seems to use some design ideas over and over, such as their input signal active filtering, their own brew of distortion and their peculiar distortion channel tone controls.
Good luck.
Title: Re: Frontman 212R help needed
Post by: bob_amos on May 05, 2009, 11:22:33 AM
J.M., I'll post it if I can get my hands on it. I have a good friend that was the production manager for the amp department at Fender. He's still there in the R&D dep't now. But I hate asking him all the time for information. I am a professional auto mechanic and electrical and air conditioning specialist and hate it when friends always ask for car information. It seems as if they are friends just for that reason, so, I don't want my friend to feel that way too. As to there being a difference, as I recall, there was but that difference may be small and not an issue. I just figured that since this project is going to be handled a few weeks down the road that I would prefer knowing that the working schematic in my posession was absolutly correct. My problem with the 212R is no gain. The volume is moderate but when turned up does not change. It seems to stay at what would be the number 2 level. This is on both channels. Again, I'll post the schematic if I get it.
Title: Re: Frontman 212R help needed
Post by: J M Fahey on May 06, 2009, 09:47:55 AM
Hi Bob.
Your problem sounds like
1)a bad pot, replace it with a similar one. or:
2)a broken/cut/unsoldered track , which is very likely since the pot is not supported mechanically, transmitting al pressure/hits/torsion/whatever to the pads to which it´s soldered.
Use a loupe and good light , start by resoldering it, it won´t hurt anyway.
Good luck.
Title: Re: Frontman 212R help needed
Post by: bob_amos on May 07, 2009, 01:20:26 AM
Thanks I'll have a look there tomorrow. I appreciate all the help I can get from you guys. Thanks!! :tu: