Have you tried the ART SLA-1 amp yet?

Since Audiogon removed the first thread related to the ART SLA-1 amplifier based on reasoning I can't really make sense of, I will re-post being careful not to advertise services. I would simply like to read peoples exerience with the unit as compared to other amplifiers. I believe some people were about to post their findings when the post went the way of the DoDo. Now, lets see if this is good enough to not get axed after having nearly 60 responses.

The standard binding posts on the amplifier can only take banana plugs and bare wire. Those with spades on attached to their speaker wires are out of luck. I recently updated the plastic shrouding from the existing binding posts with a the corresponding portion a more conventional binding post and can now use spades.

Below is an exerpt from my SLA-1 page after having used the amp for about 5 weeks:

The SLA-1 made a return to Danny's Soundtech/ATC/Kimber/(DI/O)/Marantz system with modified speaker connectors capbable of taking stacked spades. The Kimber 8TC cables are a double run of stiff cables necessitating binding posts capable of solidly connecting the wires...the experience from the first trip(see Day 19 above) used skward adapters that never really worked out. Any thoughts of interchanging hot and neutral to experiment with absolute phase were dashed in the previous evaluation....not this time around...we started with the phase flipped from the last time. The results were a return of dynamics, soundstage, ease and naturalness. Three things had changed:

No akward connectors
Reversed absolute polarity at amp connections to speakers
Addition of Jon Jon Risch twisted pair 89259 with spaced off shield

I had a mild headache resulting from being over some details on a project for most of the day...so my listening acuity and comments that follow reflect mostly what Danny heard. Prior to plugging in the SLA-1, the Soundtech Tube amp with the new JR interconnect was audioned. As Danny put it: "I'm able to listen and hear more information at lower volume levels with greater enjoyment". His conclusion is that the cable and shield have lowered the noise floor and increased the signal to noise ratio. To me the Norah Jones album sounded non sibilant in his system for the first time. In its place was a better integrated mix with certain textures to plucked string that I had not hear before but without any sibilance and all very relaxing. On the Mary Chapin Carpenter album (Come On Come On), I got the best impression of the room size and acoustic that I have heard. You could sense the witdth and depth of the recording venue and almost even sense the height of the room...quite special. Some of my listening preferences are a result of getting used to what is not right...it is that sound associated with "silver" where certain parts of the spectrum are emphasized giving the sense of more information and a larger soundstage. The quieter background of the JR cable seem to have dminished this euphonic colouration. Putting in my next favourite cable, the Van der Hul Thunderline, confirmed this. With the JR cable back in, the SLA-1 was auditioned and comments are made relative to the Soundtech amplifier.

As I have already let the cat out of the bag about the improvements(dynamics, soundstage, ease and naturalness) in performance over the previous audition, there still remained some room for improvement. Cold out of box, it initially sounded lean in the midrange but with a upward tip to the balance (this was alluded to by other reviewers) and a lightness to the bass. It still sounded very analog but very low level detail was missing.

Playing an extremely dynamic recording of a large church choir from Chesky's demonstration disk through his ATC speakers gave a wide and deep soundstage using this wide dynamic range recording. The volume controls were at the 12 o'clock position making the organ hiss very audible....the amp hardened at times on peaks at this volume levels but did not clip audibly and gave a good account of the recording.

With more warmup, some of the warmth and naturalness returned. It seems as if the stock SLA-1 errors on the side of omission did not compliment the JR cable's neurality. Putting in the Thunderline cable confirmed this as seemingly missing detail and balanced seem to have been restored (to me). To Danny, it was brighter and a more outlined presentation (what some call mid-fi) but with less inner detail due to a raised noise floor (Note to myself: Try to figure out this aspect of Danny's called noise floor and its sonic signature). If I assume the signature with the JR cable is the right one, then I I think I can hear that signature that I associate with poorer quality resistors, capcitors, wire and opamps. Eliminating this signature and improving the subtle sonic quality that makes a system listenable for hours at a time is mark of success. In its default form today, I can easily filter these slight flaws and enjoy the music. It is only in comparison to knowing what is possible that will lead to a slow evolution of the SLA-1...hopefully to the level of the Soundtech Poweramp One Tube amplifier

Swapping the speaker posts for some 5.00 ea gold plated 5 way posts is a matter of unbolting the stockers and bolting up the new ones.

No soldering or de-soldering is involved...ie, anyone can do this mod.

As far as the 1/4 inch pro jacks, i simply carefully broke the plastic housing on the interior of the amp, and bolted in the 5.00 ea gold plated replacements and soldered them to the board mounted inputs.
Almost anyone can do the second mod also and you can use your rca's direct without the use of the cheesey 1/4 adapters.

Doing these two mods improves the already amazing sonics of this little amp by letting you use your favorite spaded cables, and alowing a direct connection of high quality rca ic's and my total investement so far is 220.00. It has more detail resolution in the upper mids up than my 4k powerbloc 5 amp.
Nobody could purchase this amp and feel they did not get a lot more than there moneys worth imho.

Hi Ears,

From your posting history, I see you have had Haflers,B&K,Adcom, Classe and Electrocompaniet amplifiers in and out of your sytem driving your Thiel speakers. Now that you've settled on the SLA-1 for the interim...could you describe what aspects of the amp are lacking relative to these amplifiers.
I know longer have the Thiels or any of the above mentioned amps as i have tried to intergrate ht/2 channel in one systym. The Electrocompaniet amp was the best amp of the bunch for driving the Thiels, but i doubt the Sla-1 would work out for lack of current.
I am currently using stand mounted monitors[custom] that consist of Scan Speak drivers with Revelator tweeters and Hovland/Alphacore xovers.
These speakers go down to around 40hz and are used without subs for 2 channel, and are every bit as revealing as the Thiels from 40hz up.

I quit reading the audio rags years ago when Corey G was still writing for S-phile, so if i do not use the standard catch phrases, this would be why.
I consider this a good thing.

Anyway, the previous amps were all on the warm side of things and the electro had the most mid range and upper octave detail of all prior amps.
The Sla-1,is ultra detailed in the midrange and highs without the warmth of previous/current amps and i find the sound addicting.
There is more detail and pinpoint placement of instruments within the soundstage when the Sla-1 is in place.
The micro details whithin the soundstage are more prevalent with the Sla-i in the chain.
I do have Az matrix and Ap oval 9's hooked to it ,but have yet to use a pc that cost more than 50.00.

I find it simply amazing, that a 200.00 amp can sound this good, and it makes everything else i have heard seem far overpriced.

This amp has me wanting to mod my 4k amp, and i eventually will.
I don't no what higher praise could be given to a 200.00 amp with 20.00 worth of mods.
Vade Forrester of "Positive Feedback" magazine tried the ART SLA-1 amp during his review of the Usher X-798 speaker. As much a amp review as a speaker review as the overall sound of the system was evaluated.