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 !

Acoustic Treatment

The listening environment is one of the most important "components" in the hi-fi chain that is often overlooked. How a speaker interacts with the room it is placed in will have a dramatic effect on how it sounds to the listener.

In space scarce Singapore, most of us (except for the really lucky / well-heeled ones amongst us) have to make do with placing our audio setup in either the living room or a fairly small spare bedroom.

The typical public housing flat bedroom in Singapore measures about 3 x 4 meters. This necessitates keeping the system small, choosing speakers that do not acoustically overload the room, or resorting to room treatment methods, or a combination of all of the foregoing.

Why does the typical audiophile neglect room treatment ? Laziness ? Cosmetic issues ? Possible irate spousal response ?

Anyway, I have just revamped my listening room and taken the opportunity to acoustically treat my listening room. Unlike American homes, walls in Singapore are almost always built from brick, concrete and plaster. This results in hard reflections and a bit of bass boom.

Room treatment options in Singapore are quite scarce. Professional products are expensive due to the economic inefficiency of shipping large heavy items from American and European audio manufacturers.

DIY is an option, but lack of a garage makes construction a bit tricky. Materials such as wood and rockwool are available but require a bit of effort to track down and transport.

In consultation with Joamonte (resident acoustic treatment expert - you will find him on Singapore hi-fi forums like Echoloft (gone with the wind) and Xtremeplace, treatment was only done on one side of the room, directly behind the system. The treatment consisted of a combination of diffusor and absorption panels.



According to Joamonte, treatment of all the early reflection points could result in the system sounding too dead.

Acoustically, my listening room is not particularly troublesome. It is modest sized (about 3 x 3.5 meters), and has a fairly high ceiling. It is a regular rectangle shaped room, but is acoustically not fully closed on one end, as the wall is made out of plasterboard.

Nevertheless, the room is a little live sounding, and imaging and staging is not as sharp as it should be.

A total of 8 diffusor panels and 2 absorption panels were deployed. The two absorption panels were placed in the corner of the room, at ear level. The diffusor panels consisted of both an early model sold by Joamonte and his current production, which utilises plastic wells placed in a frame. Not much low bass treatment was required as my system does not go very low, probably no lower than 40 Hz.





























































Verdict :- Great stuff. Soundstaging and imaging are much improved. The tonal balance of the system was not affected much. Some of the obvious improvements were,

Midrange, especially female vocals – female voices were less sibilant and the level of grain was reduced.

Background – much quieter, with very low level detail retrieval becoming much more obvious. Most importantly, the lowering of background noise did not affect the “air” of the system.

Air / Ambience – The sense of air around instruments, and the fade / decay from the initial transient note of percussion and brass instruments were more prominent and longer. This seemed odd as I would have thought that acoustic treatment could have the unwanted effect of reducing this.

The panels were made by a carpenter to Joamonte’s specifications. He has also made some measurements of the room to demonstrate the difference between the treated and untreated room.

It is amazing how spending a relatively modest amount (S$1,600) could change and improve the system tremendously. Instead of spending money on expensive cables and footers, perhaps some attention should be paid to acoustic treatment.

Here are the measurements of the room with and without treatment.

An update much overdue

Rather unfortunately, it has been ages since I have last updated this blog. There have been lots of changes to my system and lots of new accessories to be covered. Stay tuned for updates on acoustic treatment, the Acoustic Zen Silver Reference II interconnect, Telos RCA caps and speaker post plugs, and much more !