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General Category => VALVE archive => Topic started by: Mike F1 on March 16, 2011, 03:12:32 PM

Title: Foreplay Vs Soul Sister
Post by: Mike F1 on March 16, 2011, 03:12:32 PM
Just like the others I'm thrilled that the Valve articles are available, thank you.
Nice bedtime reading! :)

Upon looking at the Soul Sister pre-amp schematic it looks fairly simple albeit with some potential pricey/exotic parts. (i.e Tubes, Transformers, CCS)
For those who built this preamp, how does the Souls Sister stack up to a Foreplay 2 with the Anticipation mods or a stock Foreplay 3?

To add to that, how come the Soul Sister never made it to kit form? Was it price, tube availability or noise/hum by any chance??

Just curious.. wondering if it's a worth while project :)

Thanks

Mike
Title: Re: Foreplay Vs Soul Sister
Post by: Paul Joppa on March 16, 2011, 07:35:59 PM
Very timely question!

If you look closely, you will see that the Soul Sister looks a lot like the Paramount "soft-start" upgrade, except the Sister recommends a pair of 0D3 shunt regulators while the upgrade kit has a hybrid regulator for each channel. In fact, I had forgotten that the Sister also used the 5670!

We are in the process of trying a few new ideas for line stages, and this is one of them. Our bud richardl has built a prototype and is listening to it now. First impression is very positive; we'll have more information in a few months.

I am not sure - that was a long time ago - but I think it was price that killed it at the time. The output transformers are costly. But it did, and does, sound darn good.
Title: Re: Foreplay Vs Soul Sister
Post by: Mikey on March 17, 2011, 05:14:58 AM
Hi Mike,

I've built all of the preamps you mentioned, as well as one you didn't....an Extended Foreplay 3.
To answer your first question, I'd rank the preamps in the following order:

1.  Extended Foreplay 3
2.  Soul Sister
3.  Foreplay 3
4.  Foreplay 2 with C4S

Please bear in mind that my list is subjective, and you may well prefer something different than me.

To answer your second question; yes, the Soul Sister is certainly a worthwhile project!
It is easy to build, sounds great, and the B7 transformer output can be configured for balanced output
if you'd like.  I tried it both ways, and the preamp was dead quiet in each configuration.

Here are a few photos:

(http://i3.photobucket.com/albums/y80/mpaschetto/Soul%20Sister%20Preamp/PC030001-1.jpg)

(http://i3.photobucket.com/albums/y80/mpaschetto/Soul%20Sister%20Preamp/DSC04058-1.jpg)

(http://i3.photobucket.com/albums/y80/mpaschetto/Soul%20Sister%20Preamp/DSC04059-1.jpg)

(http://i3.photobucket.com/albums/y80/mpaschetto/Soul%20Sister%20Preamp/DSC04057-1.jpg)

(http://i3.photobucket.com/albums/y80/mpaschetto/Soul%20Sister%20Preamp/DSC04055-1.jpg)

(http://i3.photobucket.com/albums/y80/mpaschetto/Soul%20Sister%20Preamp/PA080005.jpg)

Mike
Title: Re: Foreplay Vs Soul Sister
Post by: John Roman on March 17, 2011, 06:04:59 AM
Beautiful work! I particularly like the way you wired up the attenuator. To me this is art , an industrial beauty if you will.
regards, John
Title: Re: Foreplay Vs Soul Sister
Post by: chrisby on March 17, 2011, 06:21:41 AM
Beautiful work! I particularly like the way you wired up the attenuator. To me this is art , an industrial beauty if you will.
regards, John

Second that -
gorgeous work as always Mikey  -  do you have a gallery of all your "DIY" projects (as opposed to the very tasty commercial work), from which we can poach ideas - I mean garner inspiration ?
Title: Re: Foreplay Vs Soul Sister
Post by: Doc B. on March 17, 2011, 06:27:32 AM

We are in the process of trying a few new ideas for line stages, and this is one of them. Our bud richardl has built a prototype and is listening to it now. First impression is very positive; we'll have more information in a few months.

Just to keep this interesting for everyone I'll mention that as good as the circuit PJ mentions here sounds, I am currently betting on another pony. I think that these experiments with a few different line level designs could lead to another leap forward in the sound quality of some of our products, similar to the way our experimentation with four or five different shunt voltage regulator designs did a few years back.
Title: Re: Foreplay Vs Soul Sister
Post by: Hank Murrow on March 17, 2011, 06:53:19 AM
I too was excited by the original Soul Sister and subsequent Kugelis articles in the VALVE issues. So I collected parts including Mikey's B7 Cobalt-core trannies and I.A.G. transformer volume controls..... and ultimately gave the bits to Paul Birkeland of Bottlehead Customs to build one for me. The result is detailed here: http://www.bottlehead.com/smf/index.php/topic,64.0.html  I can say that the piece is absolutely quiet and sounds as good as I have heard, including the gear at the three VSACS which I attended. Front Panel Express did a good job of fabbing the chassis from Paul's drawings, and the piece is a joy to use. Paul Joppa contributed much to the intricate power supply. It really is the center of my 'final music system'!

Cheers, Hank
Title: Re: Foreplay Vs Soul Sister
Post by: Mikey on March 17, 2011, 07:53:04 AM
Beautiful work! I particularly like the way you wired up the attenuator. To me this is art , an industrial beauty if you will.
regards, John

Thanks John, I appreciate it!

Mike
Title: Re: Foreplay Vs Soul Sister
Post by: Mikey on March 17, 2011, 07:56:27 AM
Second that -
gorgeous work as always Mikey  -  do you have a gallery of all your "DIY" projects (as opposed to the very tasty commercial work), from which we can poach ideas - I mean garner inspiration ?

Not really Chris....
You'll just have to bookmark these threads for the time being!

Mike
Title: Re: Foreplay Vs Soul Sister
Post by: ironbut on March 18, 2011, 06:46:36 AM
Hey Mikey,

You should put a couple of "eyes" on the Goldpoint. It looks like some guy that's holding the whole thing together!

Reminds me of my first CD player from Cal Audio. They had an extra trace on the circuit board that was a "Where's Waldo?".
Title: Re: Foreplay Vs Soul Sister
Post by: Mike F1 on March 18, 2011, 02:23:50 PM
Thanks for the input. The pictures that were posted are great!

I'm going to try the Soul Sister circuit with a pair of GE 5670 and/or Western Electric 396A.
I also just ordered some B7's! :)

I have a box of goodies.. Caps, PT's, Goldpoint Stepped Attenuator etc so it should make for a fun & easy project to experiment with.

I love the community!

Mike