SA-11 Upgrades

The SA-11 was ahead of its time. An all-out tube line-only preamp -- a "control amplifier" -- with remote control. Wow! A 60-lb dual-mono line stage! It's larger than most power amps, and outweighs them, too! This baby is dual-mono: it has twin transformers, dual-mono vacuum-tube power supplies (13 tubes!); and uses 6SN7 octal-based tubes in the audio section -- just like my new upgrades for the SA-12/100 and SA-20/220 power amplifiers. Stepper-motor-driven 41-position stepped attenuators. It was very, very expensive (for the mid-80's) and nothing, absolutely nothing in those days could touch it. Counterpoint only made a few hundred. And according to those who have heard the SA-11, or own one, nothing, absolutely nothing on the market today can touch it.

Basic Upgrade
Premium Upgrade
Premium GOLD Upgrade

Option: Upgraded Wiring Harness
Option: Balanced Outputs
Option: Upgrade RCA Jacks
Option: Bypass Input Level Controls

Basic Upgrade

This is the place to start -- it addresses the weaknesses in the signal path. For the Basic upgrade, I eliminate the solid-state buffer cards and re-configure the tube circuit as a fully-balanced SRPP that can drive real-world loads (interconnects and power amps) directly from the Direct Outs, HP and LP Outs. You get pure tube circuitry in the signal path. You also get more detailed highs and much livelier dynamics -- a more exciting sound.
    To accomplish this, I need a couple of extra tubes, which the SA-11 already has in the seldom-used phase inverter circuit. The original SA-11 amplifying (line) stage is a non-inverting common-cathode circuit that used a single 6SN7 per channel. 6SN7's have two triode sections internally. The new non-inverting SRPP line stage requires three triode sections (to provide balanced outputs four triode sections are required). To get the extra triode sections, I use the two 6SN7's in the SA-11's phase inverter circuit -- which few people use anyway.
     There are several advantages to the new line besides the increased drive capability. First, while the original circuit was very fussy about the tube type (because it was grid-biased it could only be used with tubes that had very low grid leakage), the new circuit can be used with any 6SN7-type tube. Second, whereas the original circuit needed to be re-biased for lowest distortion with special test equipment whenever the line stage tubes were replaced, the new circuit does not need any special attention: just pop in the new tubes and you're ready to listen.
     The high-low gain switch on the front panel is disabled, too, as it depended on negative feedback through the Buffered Outs buffers to work. (After the upgrade, the gain of the SA-11 stays fixed at 22dB. Distortion typically runs less than 1% at one volt out; and frequency response is 10Hz to 120kHz into a 100K load.) And since the new audio circuit is fully-balanced, driving power amps with balanced inputs is a cinch -- just add the balanced output jacks option!

The net result is every source of audible solid-state colorations is eliminated. I also go through the signal path and upgrade the parts, starting with the coupling capacitors, which are used to transfer the signal to and from the audio tubes, from the old dry-sounding TRT/Infinicaps to more natural-sounding Dynamicaps. This makes a huge improvement in musical naturalness. Other parts in the signal path are upgraded, too: I install 1% Caddock TF020 Tetrinox, Vishay "Naked" film resistors, and Mills copper-leaded noninductive wirewound resistors, I replace all the tube sockets on the audio board (four octal tube sockets) with more reliable and better-sounding ceramic ones, and upgrade some of the indifferent-sounding capacitors in the onboard high-voltage regulators. I completely re-tube the unit.

This is a very labor-intensive upgrade, and the results show it: a more dynamic, more liquid presentation. Every time I listen to one of these upgraded units, I am taken by its natural liquidity, midrange and treble naturalness. Intertransient silence and spatiality are both improved. The sound becomes far less mechanical with these changes.

Three-dimensional imaging and in-your-face realism. The Premium upgrade includes everything in the Basic upgrade, then extends the work more deeply into the power supply section, using the liquid-sounding Continental Capacitors oil-filled caps in the dual-mono 430VDC regulators, and upgrading all the 630V pre-regulator and 900V unregulated supply filter caps to Continental Capacitors (better than Black Gate, my previous favorite). I replace all the standard silicon rectifiers used to power the several filament supplies with hyperfast FRED diodes. The net result of all these changes results in an amazingly natural and coherent sound. All tube sockets on the power supply boards (five octal tube sockets, four 9-pin tube sockets and four 7-pin tube sockets) are upgraded to reliable ceramic/gold ones.

The front-to-back layering and in-the-room three-dimensional palpability are amazing. You'll jump out of your chair.

Premium GOLD Upgrade

The direct connection to the power. The Premium GOLD upgrade contains all the work of the Basic and Premium, then takes the unit to its ultimate realization by replacing both power transformers with Plitron toroidal units. These transformers are costly, because they are hand-assembled one at a time. It takes ten weeks to get them from the time I place my order, but the improvement they bring about is just wonderful. Units with Plitron toroidal transformers just sound more musical, more dynamic, more everything that music needs to be exciting and natural-sounding. They rock.

Without putting too fine a point on it, if you don't go for these transformers as part of your upgrades, you're missing out on a big part of what your Counterpoint product is capable of.

Price for SA-11 "Premium GOLD" Upgrade: $4,300

Stock SA-11, prior to upgrade	This is Mike Savuto's Premium Gold upgraded SA-11. It's hard to see even 20% of the changes. You can just make out a bit of one of the toroidal transformers through the side of the transformer cover. The yellow, orange and green VTV caps are visible on the rear board. The solid-state output buffer cards have been removed from the rear board.
Stock SA-11	Ceramic/gold tube sockets, and two banks of four upgraded power supply capacitors (black with gold lettering) are visible below the unit's front tubes. What you can't see are the dozens of new parts on the circuit boards, and the new circuitry that makes the audio section sound magical. Savuto supplied several NOS audio tubes to try in this unit, including JAN VT-231's. His short-bottle black base Sylvania 6SN7's are pictured here.

These upgrades take an already classic piece, considered by some to be the very best line stage ever, and turn it into a show-stopper. The sound quality is wonderfully involving.

Options

Option: Balanced Outputs. There is room on the rear deck, and the new tube circuit has the capability, to offer balanced outputs. I install a pair of XLR jacks, driven directly from the audio tube.

Pricing for Balanced Outputs. Add $150 to install balanced outs.
This price is for adding the balanced outs at the same time as doing a Basic, Premium or Premium GOLD upgrade. We build the audio section a little differently if balanced outs are not ordered along with those upgrades. Add
Add setup fee to this price if optional balanced outs are added separately.

Option: Upgraded Wiring Harness. Counterpoint used inexpensive PVC-insulated stranded wire, just like you can buy at the hardware store, to connect the power supply and audio boards together. The crimped-on connectors are sometimes loose. I can upgrade internal wires to much better metal and solder the connectors on, assuring a gas-tight connection.

Pricing for Upgraded Wiring Harness.
With Acrotec 99.99997% (6N) copper wire: $267,
or with Cardas 6N Teflon Litz: $367.
Add setup fee to this price if not done with Basic, Premium or Premium GOLD upgrade.

Option: Better RCA Jacks. The jacks on the SA-11 can be upgraded to use jacks with much better metallurgy. This can be done selectively: you might wish to only do your CD and phono inputs, and the direct outputs, for example. I use direct-gold over copper CM1F-OFC jacks from Sound Connections, which mount easily and sound very, very good.

Price to Upgrade RCA Jacks to Sound Connections CM1F-OFC: $60 for first stereo pair, $25 for each pair thereafter.