Note: there is a rant first, then a question. If you dont want to hear how crappy rockford's build quality is, go right to the question, I need some help... RANT: :ranting: As I mentioned in an earlier thread, I was (once) quite partial to the rockford power amps of old.. I recently bought a defect 250M2 in the hope of fixing it and using it for the upper soundstage. I got it in the mail on thursday and took it to the engineering power lab at school to fix it up. Looks like someone already had a go at it (withsoldering skills of a two-year old...). anyway. man was i disappointed with rockfords engineering dept.! i was always happy with the sound and power of these amps, and in my opinion they looked quite good as well (oval, black bbq style). I never opened one up though. complaints: - fragile smd components placed right beside power components (powerMOS, large biasing resistors, supply caps, etc) - even more fragile rca and power jack connectors. totally cheap pieces of junk... - gain pots are squished on top of switches, they physically dont fit!!! they are crammed in, no wonder these amps needed to be hand-made, most likely the hand-made designation comes from some poor lady having to hand-solder these pots in cuz the machine couldnt do it! - very cheap PCB job... the solder pads for the powerFETs, caps and power inputs are way too small, the copper is too thing throughout the board, and soldering anything (yes, at the proper temp) makes the isolation layer peel back ...i prototyped a 3D camera over the past few summers at CSEM SA in switzerland (pics here: http://www.ece.ualberta.ca/~mstamm/pics/csem ), so I know at least a little of what makes a nice pcb. The 250M2 pcb is a mass-market, throw-away type of board, never meant to be repaired. I'll fix mine, but I'm on the lookout for a new set of amps. too bad, i always thought the build quality inside would stand up to the overall impression i used to have of this amp. Soooo... since Im now done with ranting.. QUESTION: :blink: I suppose many of you have opened up your amps. Im looking for a nice used 2ch amp of high build quality in the 100Wrms x2 range (@4ohm). Ive heard many good things about TRU/ARC/ZAPCO/USAMPS. I dont think my ears are able to distinguish between these amps' SQ, so my primary objective is to find an amp i can fix without worrying about destroying the board in the process. I'm looking to spend ~200-300USD. It will drive an as of yet undecided diy 3way comp set. I looked at this, what do you think? Zapco Reference 350 on Ebay Zapco Z300S2VX on Ebay Arc CXL2050 on Ebay I'd also like about 1kWrms (@2ohm) for bass amplification... I *had* two 250Ms in the pipeline, but after this experience Im not so keen on that anymore. I could just get a hifonics brutus, but again, a nice used mono class A/B would be sweet. Any suggestions would be appreciated! thanks guys, and sorry bout the long post. cheers, mike http://mstamm.imgaming.com
on a postitive note, rockford customer support seems to be brilliant... i asked for the schematic to the amp and got it within a working day! Punch Power 250M2 Schematic: http://www.ece.ualberta.ca/~mstamm/files/2...250M2_schem.pdf might help clear up the odd discussion on amp power supplies, etc... cheers, mike
