Passive pre and Paramounts??

[Jim R.]

Rick, 100k will likely be too high if you want the pot outside the box and will be running cabling from the box to the amps.  100k is fine if you mount mono attenuators inside the amps.  With the pot outside the box and connected by cabling to the amps, I wouldn't go over 50k, and more like 25 as others have said.  Generally you want the source to have as low an output impedance as practical (in this case it is fixed and a bit higher than typical), and a high impedance on the amp end.  When you put a high value pot somewhere in between, you are in essence, raising the output impedance of the source by quite a bit and the capacitance of the connecting cables will roll off the high end and generally make the sound less dynamic, etc.

HTH,

Jim

[shelby1420]

Rick, 100k will likely be too high if you want the pot outside the box and will be running cabling from the box to the amps.  100k is fine if you mount mono attenuators inside the amps.  With the pot outside the box and connected by cabling to the amps, I wouldn't go over 50k, and more like 25 as others have said.  Generally you want the source to have as low an output impedance as practical (in this case it is fixed and a bit higher than typical), and a high impedance on the amp end.  When you put a high value pot somewhere in between, you are in essence, raising the output impedance of the source by quite a bit and the capacitance of the connecting cables will roll off the high end and generally make the sound less dynamic, etc.

HTH,

Jim

Shoot, thanks Jim, wee bit of a brain fart there...........  I remember you guys saying that 25 would be better if building the passive pre!!!  Thanks !!!

[shelby1420]

In the past weeks I've also been experimenting with passives. Way better than just a pot is, IMHO, a transformer coupled passive,  Magnequest makes a 10k:10k unit that is very nice with a 10k pot but, as PJ says, 10k is marginal with the Seduction. My friend keto is looking for a 50k:10k transformer to load the Seduction correctly and use his 10k Penny and Giles pot. I have his 15k: 600 ohm MQ B7s and ordered a 1k P&G pot. Negative gain is perfect in my system with 2A3 Paramounts but my speakers are 106 db efficient. Nothing like experimenting in your own system.

I have deided to purchase the AVC from Intact audio and go this route instead, thanks for all your help guys!!

[8452]

I think you will like the Intact AVC's. I have been using a pair between my Paramounts and Seduction for about a year. I had tried two active preamps prior and found that they had too much gain (or the Paramounts do). The Intacts  sound wonderful; very transparent, no restriction of dynamics.  My speakers are over 105dbw efficient, my cartridge's output is 2.5mv, and cable length is about 2m from Seduction to Paramounts. I'm thinking about the soft start upgrade for the Paramounts, but given its negative affect on gain, I'm not sure. Anyway, good luck with your project. Post your impressions when you are done.

[shelby1420]

I think you will like the Intact AVC's. I have been using a pair between my Paramounts and Seduction for about a year. I had tried two active preamps prior and found that they had too much gain (or the Paramounts do). The Intacts  sound wonderful; very transparent, no restriction of dynamics.  My speakers are over 105dbw efficient, my cartridge's output is 2.5mv, and cable length is about 2m from Seduction to Paramounts. I'm thinking about the soft start upgrade for the Paramounts, but given its negative affect on gain, I'm not sure. Anyway, good luck with your project. Post your impressions when you are done.

You are 100% correct, I do love the Intact Modules located here --http://intactaudio.com/module.html --  so easy to instal and they sound lovely, or more accurately they get out of the way and let the Paramounts do there thing, so very very clean, superb bass response and a general joy to listen to music again!!!

[Paul Joppa]

...I'm thinking about the soft start upgrade for the Paramounts, but given its negative affect on gain, I'm not sure. ...

The upgrade with 5670s will have 4 to 5dB less gain than the original. The Intact switching is unusual, but if you have 4-5dB to spare then it should be no problem.