Rowe CD100E Amplifier recapping?

[bjm-maxx]

I am wondering if my jukebox is needing to be recapped. Not sure what symptoms I would expect to hear. This unit has dual 7 channel frequency equalizers and leaving the knobs in the middle sounds best. Any adjustment and the sound really tends to get noticeably muddier but in the middle is pretty good. I am sure if I went rooting around I would find some out of spec electrolytics capacitors but is there anything to really suggest pulling it out and working on it.

Also wondering if someone in the Ottawa area does this kind of work?

Thanks in advance.

[semicolin]

Centek out at St. Laurent and Walkley does this sort of work and so does Hi-Tronics.

That said, through-hole re-capping is one of the easiest electronics repairs you can do; for under $50 you can buy every tool you need to learn.

Now... one thing about graphic eqs on jukeboxes that you should know is that they're engineered to be flat to match the internal speakers. If you're turning the knobs and it sounds worse, well, what do you expect? Of course it will sound worse. When you're off zero you're telling the amplifier to distort the signal that goes to the amplifier/speakers.

My first job in high school was to be a sound guy's assistant, and the first thing we did on every service call for bad sound was to flatten the EQ and go from there. EQs exist to compensate for imbalanced speaker setups, poorly chosen crossovers, and to generate service calls at wedding venues when the owner's brother sets them to look like the cheshire cat's grin.

[bjm-maxx]

I am actually reasonably experienced at soldering and have all the right tools. Its just the shear scope of the job that is a worry. Any suggestions for sources of capacitors? I have ordered many times from Digi-Key but caps this large are getting hard to find and prices are going up. I have a ESR tester so I should be able to sort out which are actually neededing replacing.

I hear what you are saying about the equalizer. The manual starts you off with everything flat, then tells you what you should adjust for the type of room you have, mostly softening the top or the bottom if the room was refelctive or not. What I found is regardless of what I did, the sound seemed worse. Seems like maybe the equalizer section is performing poorly. From the schematic, it has by far the most electrolytic caps in it. There are 14 equalizer circtuits all replicated for each channel and band. Lots could go wrong in there.

The high power amp seems only to run at full output with all the volume attenuation and adjustments coming from the equalizer section. The only caps in the high power section are 2 huge smoothing caps for the DC power supply.

I never heard these things when they were new, were they a high quality sound, or more a tough durable design meant for crowded restaurants? I am not sure if I am asking too much of this thing.

[semicolin]

For your last question, they were definitely never intended to be high fidelity. They were intended to be reliable with as few parts as possible, and never powered off.

That said, recapping with parts from digikey shouldn’t be that expensive. Sure, big body caps with terminal screws are pricey, but if you aren’t wedded to the form factor you can get reliability and ratings that are just as high in much smaller packages.