RE: With modern sources putting out 2.5v why do I need a preamp

Charles,

I don't know if this will help or hurt - but I'm going to tell my anecdote anyway.

A while back, I had and Adcom GTP-350 tuner preamp, and an Adcom GFA 535 MK II power amp.

My CD player had a 100 ohm output impedance, and the power amp input impedance was 100k ohms. Pretty much an ideal situation for a passive. As it turned out, the GTP-350's volume pot was about the right impedance for a passive system. So I bypassed all the active circuits in one channel, making it passive; but leaving the other channel active. Then I carefully arranged an AB of the active vs passive channels. I should add at this point that I had previously padded the circuits for flat response to better than 0.1 dB.

Bottom line, I could hear no difference in the passive vs active channel. So I reconnected all the active circuits and lived happily with the preamp for several more years. I guess I'd call that a neutral preamp.

Jerry

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Follow Ups Full Thread

Topic - With modern sources putting out 2.5v why do I need a preamp - airtime 07:40:40 08/13/16 (20)

Yes - Awe-d-o-file 17:01:05 08/17/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp - Bold Eagle 14:09:23 08/17/16 (0)

Palutris explained it pretty well but you also have to consider - Michael Samra 16:51:04 08/14/16 (0)

If you use a high gain amp, you just need a volume pot. - richardl 12:49:03 08/14/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp - Palustris 12:12:33 08/14/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp - Crazy Dave 11:51:40 08/14/16 (0)

I remember that topic having come up ten years ago - E-Stat 11:08:15 08/14/16 (6)

Flavor - airtime 11:40:31 08/14/16 (5)

Hmmm - E-Stat 12:25:19 08/14/16 (4)

RE: Hmmm - Michael Samra 16:17:07 08/14/16 (3)

RE: Hmmm - E-Stat 18:21:45 08/14/16 (2)

RE: Hmmm - Michael Samra 18:08:57 08/15/16 (1)

RE: Hmmm - E-Stat 19:15:14 08/15/16 (0)

" throwing away signal level so that a subsequent gain stage can make it back up" - 1973shovel 19:11:22 08/13/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp - fredtr 15:54:00 08/13/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp - mark.korda@myfairpoint.net 15:44:37 08/13/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp - Iain42 13:48:24 08/13/16 (0)

Interesting on the CJ - spindoctor 13:27:32 08/13/16 (0)

impedance matching/buffering nt - viridian 10:47:50 08/13/16 (1)

and/or "drive" to the first stage of the power amp (nt) - mhardy6647 11:18:58 08/13/16 (0)

Follow Ups

RE: With modern sources putting out 2.5v why do I need a preamp - Bold Eagle 14:09:23 08/17/16 (0)

RE: With modern sources putting out 2.5v why do I need a preamp

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