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September 24, 2022, 06:47:08 PM

Author Topic: Moreplay query re pot and gain  (Read 485 times)

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Offline Flyinggode

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Moreplay query re pot and gain
« on: January 23, 2022, 04:14:56 PM »
Hello all,

I am thinking of buying a Moreplay as an alternative to my transformer based preamp that I currently use with a Schiit Aegir power amp and high efficiency Four Pi loudspeakers. I bought the Aegir on the strength of the Steve Guttenberg review. I am also enthused by his review of the Moreplay. I have tried an active preamp recently - more accurately the pre part of a vintage integrated Sansui amp that I bought for my son. It introduced some oomph and some warmth that is missing with the TVC preamp. Hence the interest in the Moreplay.

My question is in two parts. Firstly, can I use a 50kohm pot in place of the 10kohm one that comes with the kit? I have a rather nice DACT 50kohm pot. In the past, when using active preamps, I have found the pot to have a significant influence on the sound, and have rewired the pots in shunt mode. Secondly, can I reduce the gain if I find there is too much, as Steve mentioned in his review? My speakers have a sensitivity of 98dB at 1m for 1W. I would prefer to do this, if necessary, without using a resistor-based RCA plug attenuator, as I suspect that the resistors would be relatively cheap and would color the sound.

Any thoughts or advice would be greatly appreciated.

Cheers,

Mark

Offline Paul Joppa

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Re: Moreplay query re pot and gain
« Reply #1 on: January 23, 2022, 06:38:20 PM »
The Moreplay, like the BeePre, places the level control after the tube, instead of the usual position at the input. This is primarily because it reduces the noise and microphonics when used with highly sensitive speaker/power amp combinations. But it also means the level control determines the output impedance, and a higher impedance control will reduce the ability to drive cable capacitance. We don't recommend changing the impedance of the control for that reason.

We are still working on the best way to reduce gain for systems that have too much. The planned upgrade to switched gain controls will probably help - it's just too early to tell for sure.
Paul Joppa

Offline Flyinggode

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Re: Moreplay query re pot and gain
« Reply #2 on: January 24, 2022, 07:20:44 AM »
Hi Paul,

I see. That makes sense.

All the best,

Mark

Offline hddeluxe1

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Re: Moreplay query re pot and gain
« Reply #3 on: January 24, 2022, 11:54:21 AM »
    Hey Mark,
  Just a FYI. I'm running a pair of Klipsch Forte II  that are 99db through a pair of KT-88 mono's with my Moreplay. Best move I ever made.
 Was previously running a hybrid  Counterpoint SA-3000. :D
Joe "Pug" Stricker
 Moreplay preamp with 6v6-cv509's
 Reduction phono preamp with integration upgrade
 Quicksilver KT-88 monoblocks
 Fluance RT-85 TT with Ortofon 2M Blue
 Teac A2300S RTR
 Klipsch Forte II's

Offline Flyinggode

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Re: Moreplay query re pot and gain
« Reply #4 on: January 30, 2022, 07:24:41 AM »
That sounds very encouraging. So no need to attenuate the output of the Moreplay? What position do you you turn the pot to typically? Is it restricted to 7 to 8 o'clock?

Offline Paul Birkeland

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Re: Moreplay query re pot and gain
« Reply #5 on: January 30, 2022, 07:31:03 AM »
How much gain does your power amp have?  How much output voltage do your sources have?
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Flyinggode

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Re: Moreplay query re pot and gain
« Reply #6 on: January 31, 2022, 04:29:58 PM »
I am using (mainly) a Lounge Audio LCR Gold and Copla Silver with a Schiit Aegir. I think the output of the former is 7V, and the gain of the latter is 22dB.

Offline Paul Birkeland

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Re: Moreplay query re pot and gain
« Reply #7 on: January 31, 2022, 06:35:20 PM »
Oof, I would turn down the 7V source if you can.  If it had adequate current to drive a loudspeaker that output level would already be 6W.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Flyinggode

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Re: Moreplay query re pot and gain
« Reply #8 on: February 01, 2022, 04:30:45 PM »
Maybe that was wrong. I think perhaps the phono amp output voltage is 0.3V. The cartridge produces 0.3mV. The phono amp gain is 60dB   ::)

Offline Paul Birkeland

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Re: Moreplay query re pot and gain
« Reply #9 on: February 01, 2022, 04:36:32 PM »
Yes, that would be 0.3V of output, which is somewhat low but completely usable.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Flyinggode

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Re: Moreplay query re pot and gain
« Reply #10 on: February 01, 2022, 06:06:50 PM »
Excellent.
Thanks Paul!

Offline oldtriode

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Re: Moreplay query re pot and gain
« Reply #11 on: February 05, 2022, 02:41:14 AM »
"I have tried an active preamp recently - more accurately the pre part of a vintage integrated Sansui amp that I bought for my son."

Just curious, which Sansui amp's pre-out are you using?