Cosmic 5000+COGRAM400: Amplifier Aux1 Aux2 and Phono input voltages?


Mar 29, 2015
1. Just wanted to know if I could drive an amplifier using PC-out?
2. What are the input voltage ranges?

(someone gave me a broken(possibly) to salvage/sell.. Cosmic 5000 amplifier + COGram4000 turntable + 2 speakers)

I was wondering if I could connect my PC to it and use/test the amp.
also, wrt the turntable - when I place the arm (lower it using the lever) it just slides away to the center of the LP without actually doing anything - why is that?

Does anyone have any links to the original manual/datasheet/literature?

did some testing - one channel of the amp is 'weak' there is output but nothing compared to the other (so speakers are working) but the turntable acts weird and the amp needs to be opened up
When you get the amp working, you can feed the output of your computer sound card to the AUX-1 or AUX-2 inputs.

I suspect the cartridge on the TurnTable is broken, to begin with.

If you want to record from the Turntable (after geting the TT & Amp repaired) you need to connect the TT to the Phono input of the amp.
Amplifier REC Out to your Sound card Input.

You will need to use suitable software (lots of freeware available) on yr computer, to record.

All The Best !
why does the amp have 4 outputs for speakers? I opened up the amp and there seem to be two channels - 2x2 power transistor? Any idea what Class/config is this? Push pull, Class AB? Would you guys be able to advice on some of the components that I am unfamiliar with.. (I have worked with rectifiers - that stuff I am familiar with)

The upper two PAIRS of speaker plugs are paired to one amp and the other four speaker plugs are paired to the second amp.. Upper seems to be flaky (low output), lower pairs work as in I get clear audio BUT in the lower pair of outputs I can't use one set of plugs.. and this behavior is seen with the upper as well (absolutely no output on one set of plugs and low output on the other)

Anyhow I've got audio on one spkr and that's worth it :) since I was using headphones not so long ago

do the speakers have polarity? How would you open them? It has A+B marked on the 'Speakers Off' and 8ohms marked on the VU meters? Does it mean that the speakers are driven in parallel 4 ohm load? But what's the significance of marking the two channel/on-off buttons like that?

A single speaker works fine at Port 4(bottom most).. and Port 2.. so the amp is fine..
Could someone tell me what Port 1, 3 are for?

ah the speaker is busted - 8ohm resistance on one and oo on the other - any idea how to open it up 'Cosmic' (via the front or the back) what material do they use for the rear?

(yes - A+B mode is basically both buttons depressed to drive 2x8-ohm spkrs each connected to Port 2,4 respectively - the amp drives my 8ohm philips) but I still can't figure out what Port 1,3 are??
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