[Steve]

Hi Anand,

Yes, and there is more. As you already know, so many things make a difference.

Cheers.

[HT cOz]

Actually the output impedance is 600 ohms.

How would this pre-amp perform with an amp with 3,300 ohms input?

Thanks,
Robert

[Steve]

How would this pre-amp perform with an amp with 3,300 ohms input?

Thanks,
Robert

Would lose bass and might have some distortion, but there is a 5:1 ratio. Bi-amp is possible if one desired.

Cheers.

[Steve]

In terms of wiring the circuit board to chassis parts, things are straight forward. Install regular chassis parts and wire. This includes AC power wiring, and input jack wiring to selector switch etc. By the way, there is no SS in the direct signal path.

1) Install board on chassis, using standoffs supplied.

2) Solder labeled ground wire to chassis, and 2 AC power wires to board

3) Solder 2 labeled wires from board to LED

4) Solder 2 labeled wires from board to each section of the volume control. There are two sections.

5) Solder 3 labeled ground wires from the board to the right channel input jack ground lugs. (Basic model, 5 with Standard model.)

6) Now solder 3 labeled ground wires from the board to the left channel input jack ground lugs.

7) Solder 1 labeled ground wire to the right output jacks ground lugs.

8 ) Solder 1 labeled ground wire to the left output jacks ground lugs.

9) Solder labeled signal output wire to the right output jacks center terminal.

10) Solder labeled signal output wire to the left output jacks center terminal.

A link is provided on my 7A kit page with assembly instructions, schematics, and photos. (A schematic for wiring the RCA input jacks to the selector switch, from the selector switch to the balance control, from the balance control to the volume control.
I provide two simple AC power schematics.)

One can purchase any or all chassis parts from me. Check out the 7A kit page for a list.

When finished, get ready for musical heaven.

Cheers.

[xsb7244]

Did WC build the 7A?

[WC]

Not yet. Might be next summer before I get around to it. I need to get the funds together first so I can purchase the kit. 

[Steve]

Posted a couple of reviews here. Customers find it quite impressive.

http://www.sasaudiolabs.com/review4.htm

Cheers.

[poseidonsvoice]

Congrats Steve. You really should be proud for bringing great tube preamp design to the masses and of course your lovely support of us diy'ers 

Anand.

[jackman]

I owe Steve a review on the 7A.  It opened my eyes (and ears!) to the quality and amazing value of SAS.  I don't know how he does it but Steve's preamps are the best I have heard. 

I bought the finished version of the 7A on a whim because I heard very good things about other SAS preamps.   My first intention was to try the DIY build but I spoke with Steve and he had a demo model for sale.  It arrived perfectly packed and I plugged it into my system.   After a couple songs, I thought I was hearing things because the imaging of my system was noticeably better.  Also, the highs were more detailed but not harsh in any way.  I switched back and forth between the 7A and my preamp and confirmed what I was hearing.  The 7A did everything right. 

I'd love to put the 7A up against some big $$$ preamps because it is a special component and I belive it would surpass several expensive and popular preamps (in the beautiful sound department).  The 7A is very simple in appearance but the sound is shockingly good. If you like holographic 3D soundstage with great detail and silky highs, spooky-good mids, you shoud try the 7A. 

The most interesting thing about the 7's sound is that is had more detail than the other SS preamps I have owned and auditioned.  It does not add any tube "sweetness".  Highs and details are all there but harshness and sibilance is not.  I liked it so much, I immediately jumped at a 10A.  The 10A does everything the 7A does but has more "body" to the notes.  Bass is more authoratative and image is a bit more 3D.  The 10A is like the 7A on steroids.  Both preamps are excellent and I could easily and happily live with either in my system. 

Lastly, I highly recommend SAS IC's.  They have not left my system since the day I installed them to "test" them out.  Very affordable and great sounding. 

I'm saving up for some SAS amps! 

Cheers,

Jack

[bunky]

I have spent hours on the phone with Steve chatting about all things Audio and he is a very nice and very smart guy.he is willing share alot of information about his designs,Steves biggest edge besides having a obvious golden ear is that he has his own propriatary testing methods that he uses on his preamplifiers and IC cables to tweak them to Sonic perfection   

[Steve]

Thanks for the compliments guys. I have worked with all types of designs, parts, tubes since I was a kid (heard many, many other designers as well, helped college kids etc), and over the decades incorporated the best.

I see Shindo has a similar philosophy. No 50lb power transformers per channel, or 150,000uf of capacitance (actual examples from other forums). If they need it, then the design is very poor.

One problem with sonic signatures/colorations/flavors is that each instrument and voice has a different harmonic structure and will be affected differently. I think we all wish the most natural, organic, yet transparent music possible.

Consistency in natural, organic sound quality, from component to component, and absolutely minimizing sonic signatures are very difficult to achieve, even in the best components.

The above requires parts with little if any sonic signatures, tight 0,5% tolerance in certain critical areas. The latter can be achieved with capacitors at reasonable cost. Other ways are much more expensive, with no guarantee of the tolerance, or the tolerance will hold for any time frame.

Once absolute minimum sonic signatures/colorations/flavors are achieved, then one can use the reference when designing at lower price points. This was a real plus when designing the 7A.

Cheers.

[Steve]

Thanks Bunky. Addressing Bunky's comment about listening tests. First, components may spec the same yet sound quite different, be perceived quite differently. This can occur due to minor FR differences, masking distortion etc.

Manufacturers "voice" their components in their "reference" systems.
Mine are listening tested using proprietary testing methods.

The difference between the two testing methods is that the "voiced" component's quality is dependent upon the quality of the "reference" system. My testing is designed to obtain the sound quality of a component in absolute terms.

My goal is to absolutely minimize sonic signatures/colorations/flavors for better, more natural sounding music.

The 7A also has adjustable gain (change tap, 3.5db, 10db gain) to better adapt to one's system, and allows greater mechanical range of the volume controls.

Cheers.