New amp and volume control

[Karl5150]

Paul, does the less than optimum input resistance of the Harrison Labs units apply to BH integrated amps as well?
Karl

[Paul Joppa]

All Bottlehead amps, integrated or not, have an input impedance of (I think) at least 30K and are compatible with all Bottlehead preamps. Of course  :^)

Any amp or preamp with an external attenuator (such as the Harrison or Rothwell devices) installed at the input will present the impedance of that attenuator to the driving preamp.

To be fair, I am currently using 12-dB Harrison Labs at the input of both my Foreplay III and my Paramounts, so both the Eros and the Foreplay are driving 10K impedances. It's not a huge problem, but I do intend to acquire some Rothwells soon. The parable of the cobbler's barefoot children does come to mind!

[Mmaxed]

Just got my Moreplay going today.  Replaced a Schit Saga.  Needed more gain than the Saga, but Moreplay is tooooo much.  What would anyone recommend for attenuation?   

[Paul Birkeland]

I would start by asking what issue is presenting itself with the gain of the Moreplay?  For an active preamp, the Moreplay has incredibly low gain, so anything beyond a -6dB attenuator will take you back below where you were with the Saga.

[Mmaxed]

Yep, I was debating between -3 or -6 db.  With the Saga on vinyl the pot was sometimes maxed out.  Yeah it was loud.  With the Moreplay I only have maybe 10-15 degrees of rotation between nothing and too loud.  Would like a little more range on the pot.   

[btol]

Good choice, IMHO.

When they come, I'd appreciate it if you would measure the input resistance. The Rothwell 10dB measures 30Kohms, but I have not been able to discover the resistance of their 20dB unit.  These are higher than the Harrison Labs (10K for the 12dB), and I was about to recommend the Rothwells as preferable for that reason. 10K is a difficult load for Moreplay - it will work, but gain and peak output are reduced.

Forgot to mention that I got the Rothwells that are made for use on your source (in on the male side/out on the female side). Any concerns with impedance matching between my DAC w/ Rothwells and the Moreplay? Happy NYE!

[Paul Birkeland]

https://forum.bottlehead.com/index.php?topic=4295.0
Crack FAQ 3/4 applies to this situation.  If you want -3dB of attenuation, use a 3.65K resistor where the 75K resistor goes in that mod, then use a 75K resistor where the 33K resistor goes.

[Paul Joppa]

Yep, I was debating between -3 or -6 db.  With the Saga on vinyl the pot was sometimes maxed out.  Yeah it was loud.  With the Moreplay I only have maybe 10-15 degrees of rotation between nothing and too loud.  Would like a little more range on the pot.

Something is wrong here. A volume setting of just 10-15 degrees should provide more than 30dB attenuation below full volume. Most of this thread has been talking about the solution, but I am not convinced the problem has been adequately identified.

Just sayin'  :^)

[btol]

Forgot to mention that I got the Rothwells that are made for use on your source (in on the male side/out on the female side). Any concerns with impedance matching between my DAC w/ Rothwells and the Moreplay? Happy NYE!

Would love to hear your thoughts. I suppose impedance matching is mostly a concern when the attenuators are on the amp inputs...

[Mmaxed]

Something is wrong here. A volume setting of just 10-15 degrees should provide more than 30dB attenuation below full volume. Most of this thread has been talking about the solution, but I am not convinced the problem has been adequately identified.

Just sayin'  :^)

Very intuitive.    I changed the resistors on the amp so that it has a little less gain and learned to turn the loud knob more slowly.  Also the sound is more dynamic with the Moreplay making it seem louder than it did before.  More later.