Advice on how to test Adcom GFA 535

[natlus]

What I thought was a simple question(and maybe it still is): how can I test a found (only on NYC's upper east side is the trash so interesting) Adcom GFA 535 amplifier? The second question is: what make a nice preamp partner, given the Adcom works properly? I would prefer to spend less than 200$ on a vintage unit. Any advice or even website resources welcome.

The amp powers up, proper light goes on--but I have no separate preamp. What I do have is my current stereo system, which includes a vintage Yamaha 610II integrated amp. I was wondering if I could feed the adcom through the aux. of the Yamaha, and be able then to use its preamp section. Or perhaps I can feed a source (CD player) through the Adcom, but then how is the volume modulated?

In any event, I am surprised how perplexing this is, so perhaps there is such an obvious answer that it evades me. Thanks in advance.

[02audionoob]

If your integrated has a preamp-out connection, you could run that to the amp and then control the volume with the integrated. Don't connect a source to the amp unless the source has an output control. The amp cannot be connected to an Aux connection on the integrated.

With the GFA-535, I would recommend the GFP-555 preamp, which is usually available on either Audiogon or eBay for prices within your budget. If you want a tuner with your preamp, you could probably get a GTP-400 within your budget. Also a good match, if you don't need multiple sources, would be to connect a GCD-575 directly to the amp. It has a volume control.

All that said, my first choice in this situation might be the Adcom SLC-505. It's a non-powered switch box with a balance and a volume control. It's passive...no preamping occurs.

Last comment...If the amp doesn't work, check for round glass fuses inside.

[E-Stat]

What I thought was a simple question(and maybe it still is): how can I test a found (only on NYC's upper east side is the trash so interesting) Adcom GFA 535 amplifier?
Gotta hook it up appropriately (different approaches - later) , feed it a signal and see if it drives a pair of speakers!


The second question is: what make a nice preamp partner, given the Adcom works properly?
If you don't have a turntable and need the phono stage, I would agree that a passive switchbox would be ideal.


I was wondering if I could feed the adcom through the aux. of the Yamaha, and be able then to use its preamp section.
Wrong direction. Think of the signal flow. Source (CD player, tuner, etc)-->pre amp-->power amp-->speakers. The aux input on the integrated then feeds its preamp and power amp. You can't daisy chain amps back into other amps.


Or perhaps I can feed a source (CD player) through the Adcom, but then how is the volume modulated?
That is the right direction. For testing, you could do just that with a low output CD. Most CD players have a nominal 2 volt output (some are higher) and the Adcom has a 1 volt sensitivity for full output. So, a given player may be a bit too much. Maybe not. In any event, you really don't need an active preamp stage in this situation unless you plan to run long cables. While I have a preamp in one of my systems, I use it only with the vinyl source. I built an attenuator box for the CDP

rw

[markw]

For a Q & D test to see if the beast works, you could hook up an MP3 player or a portable CD player. While not ideal sources (impedance, level, etc), these both have volume controls to keep the noise at a reasonable level and will work in a pinch.

All you need is a simple and cheap 1/8" stereo mini plug to two RCA plug cable. Check Radio Shack or a well stocked dollar store for these.

If you don't get sound with this (and you have speakers connected correctly) then you have a doorstop.

[natlus]

OK, so I could even use my Tivoli iPal(radio)...
Thanks again