Wednesday, July 14, 2010

Cary Audio SLI-80 Signature Special Edition

Cary Audio's SLI-80 Signature Special Edition amp is now in the house !

Jaguar blue finish.

Output tubes - KT88, 6550/KT88, EL34, 6CA7. Choose your favourite poison.
Rear socket and trim pots are for bias adjustment

WBT Binding Posts
Also functions as a headamp. The headamp runs through the tube circuit and is not the usual separate opamp circuit

Initial impressions were that of a very powerful sounding amp with good grip on the bass (not always a given with tube amps), but a slightly coarse midrange and moderate resolution. Thankfully, the sound opened up and the coarseness disappeared after a few hours of play time.

It runs even hotter than my Cayin A-88T which tells you something !  Don't even think of placing this in an enclosed cabinet.

Like the Cayin, the SLI-80 is based on a pair of KT-88 power tubes per channel in push pull configuration, with 6DJ8/6922 (the Cayin uses 6SL7 tubes here) input tubes and a 6SN7 phase splitter. The SLI-80 may also use KT-66, 6550 and EL-34 power tubes. Power output using KT-88 tubes is 80 watts per channel in ultralinear mode and 40 watts in triode mode.

The power supply is choke loaded and tube rectified by a pair of 5U4 rectifier tubes. 

Noteworthy features include basic remote control, switchable triode / ultralinear mode and a headphone output (run from the tubes and not opamp based).

Stock tubes supplied were EH KT-88 power tubes, EH 5U4GB rectifier tubes and EH 6922 input tubes. The 6SN7 tubes supplied were labelled Cary but internally look exactly like Chinese Shuguang 6SN7 tubes.

The Cary labelled 6SN7 tubes were soft, warm and not particularly open, so they were quickly substituted with EH 6SN7 tubes, which resulted in a fairly bright and fatiguing presentation. The EH 6922 tubes were substituted with NOS Mullard tubes, and the EH KT-88 tubes were replaced by Genalex Gold Lion re-issues. This resulted in a fuller and more liquid presentation.After some experimentation, the EH 6SN7 tubes were replaced with GE 6SN7 GTA vintage tubes.

Driving my Focal Micro Utopia BE speakers, the Cary sounded best in triode mode. Ultralinear had more slam and authority but sounded a bit rough and bright in comparison. Strangely, my Cayin A-88T sounded better with the same speakers in ultralinear mode.

The Cary seems quite hard on the rectifiers, and I experienced arcing more than once when switching the amp on. Some audio forum posts suggests that this is due to excessive capacitance being used immediately after the tube rectifiers, but I won't comment on this since I did not open the amp to check the power supply layout.

I also do not like the stock equipment feet which feel and look like sorbothane feet. In tropical weather, they turn greasy and sticky rapidly, leaving unsightly marks all over your rack.

Sound wise, these problems are rapidly forgotten. This amp sounds wonderful. It is certainly not the most transparent amp around, but it did have just a smidgin more resolving power than the Cayin A-88T it replaced. What is gains over the Cayin is a much bigger presentation in the form of a very expansive soundstage and excellent bass authority (for a tube amp). The Cayin projects a flatter soundstage, with image sizes comparatively smaller. 

Compared to my Almarro A-318B, the Cary has a warmer and thicker midrange and more extension and air in the high frequencies.

Tone is also more forgiving, with a more liquid and easy going presentation, without sounding dark or shut-in. In comparison, Cayin amps have a more solid state like sound, and may even be argued to be more neutral. If you prefer a slight rose-tinted glow to the midrange and the "wet"type of highs, look at the Cary first !


horchai said...

How abt some tube rolling in the pipeline when the amp is runned in? SED c wing kt88, sed 6550, etc :)

Eric said...

Actually besides the KT88 / 6550, the amp also takes EL34 tubes. Anyway, I will be experimenting more on the pre tubes first

horchai said...

that's very interesting. By varying the biasing voltage?
I've full music 12ax and create audio 12ax7 if you wish to try next time.

Anonymous said...

Swee talkin comment on SLI80