Fans of Audio Research Corporation?

[GKTAUDIO]

Dunno yet, but I picked up a much-unheralded SP-4 a few weeks ago in beautiful condition for $150, replaced all electrolytics, replaced all the tantalums with high quality electrolytics, replaced two polyester output caps with pp, replaced some 1meg resistors, cleaned up pots and switches, and did a few other odds and ends. It sounds wonderful, though I expected not to care for it based on what people have written about it. I have Accuphase, APT (updated and upgraded) and Threshold to compare it to, and it is quite enjoyable to listen to for hours at a time

Not the quietest - it's pretty high gain and there is some slight hiss with the volume cranked (likely the 30 year old carbon comp resistors), but at actual listening levels, it's quiet, has good dynamics, and wide tone control range, and good definition. The case is built like a tank, but the circuit board, not so much.

Recommendations, anyone, for another model to look for to repair/update? I'm giving this one to my brother, so will start looking.

 

[MarkD]

I've got a Reference Phono 2SE phono stage and a Reference 150SE power amp. Love the air that the amp adds to the sound.

 

[930turbo]

Dunno yet, but I picked up a much-unheralded SP-4 a few weeks ago in beautiful condition for $150, replaced all electrolytics, replaced all the tantalums with high quality electrolytics, replaced two polyester output caps with pp, replaced some 1meg resistors, cleaned up pots and switches, and did a few other odds and ends. It sounds wonderful, though I expected not to care for it based on what people have written about it. I have Accuphase, APT (updated and upgraded) and Threshold to compare it to, and it is quite enjoyable to listen to for hours at a time

Not the quietest - it's pretty high gain and there is some slight hiss with the volume cranked (likely the 30 year old carbon comp resistors), but at actual listening levels, it's quiet, has good dynamics, and wide tone control range, and good definition. The case is built like a tank, but the circuit board, not so much.

Recommendations, anyone, for another model to look for to repair/update? I'm giving this one to my brother, so will start looking.

Hi GKT ,

I’ve never tried solid state audio research products . But if you prefer transistors , I think the LS 3 is a good candidate but it does not have a Phono stage . But if you love tubes and on a budget , the SP12 and SP16 are good candidates at least both have a phonostage.

Hope this helps,

930

 

[BillWojo]

I just picked up a SP8 Rev5 that's in beautiful condition. Build quality is extremely nice and I'm loving the sound. Something magical about these older ones with the 12AX7 tubes. I can see why they are in demand and highly sought after.


BillWojo

 

[GKTAUDIO]

Hi 930,
Thanks for those leads. I can go either way - SS/tube, or phono/line only. I have a variety of phono preamps and SUTs to play with, which may open up options for the next preamp. Am I correct that most of the ARC preamps with phono are MM only, with MC as options?
So many circuits, so little time.
Thanks again!

 

[Blue Shadow]

@BillWojo can you talk about the differences between your 8 and that newer unit you have?

 

[E-Stat]

I just picked up a SP8 Rev5 that's in beautiful condition. Something magical about these older ones with the 12AX7 tubes.

??

They've always used a mix of 12AX7 (ECC83) and 6922s (6DJ8) with some variations in other tubes used. Just like the SP-6 on which they were based.

Audio Research database SP-8

 

[BillWojo]

The ones that mixed the 12AX7's and the 6922 tubes always used the 12AX7 tubes in the gain stage and rolling them has a big effect. Rolling the 6922 tubes doesn't make any or much difference.
Actually it's very cheap to roll tubes in my SP8, the first gain tube in either the line or phono stage makes the biggest difference.
Since the 12AX7 is a dual triode it handles both the R and L channel in a single tube. Find a good tube that is fairly well matched internally and your good to go.
6922 tubes get pricey real quick for the better ones. The 6H30 have no substitute, your stuck with EH brand.
12AX7 tubes are very common and even the better ones are not that expensive plus you only need one for each stage.

BillWojo

 

[E-Stat]

The ones that mixed the 12AX7's and the 6922 tubes always used the 12AX7 tubes in the gain stage and rolling them has a big effect.

According to the arcdb link I provided and the Audio Research brochure, ALL of them used a mix of tubes.

Since the 12AX7 is a dual triode...

As are virtually all small signal tubes.

The 6H30 have no substitute, your stuck with EH brand.

Stuck? They have no equivalent in terms of linearity and low output impedance.

 

[BillWojo]

E-Stat, it technically make's a great tube with super specs but I don't listen to specs.
My LS15 uses 4 pieces of 6922, not a mix of tubes as do many other ARC preamps and line stages. Some of them mix 6922 or 6H30 tubes with silicon as well.
I really enjoy the sound of my SP8 with my Mac MC40 amps and Altec's. Makes beautiful music.

BillWojo

 

[E-Stat]

Makes beautiful music.

All ARC products make beautiful music.

Maybe I'm not understanding your point. I took it to mean that yours was a unicorn that only used 12AX7s. All of the older ARC preamps used them at one point or another in the circuit. Including the SP16 from 2001 which actually did use them exclusively.

 

[BillWojo]

The first two tubes in each stage are 12AX7's and the third tube in each stage is a 6922. The other tubes are used in the PS and are a 12BH7 and a 12AT7. Rather unusual tubes to use in a PS but ARC is known for building very stiff PS and I'm in no position to argue with the engineers that designed this.
This thing is filled with very high quality resistors and film caps. Probably only about 10 or so carbon comp resistors that I will eventual replace.
The chassis construction is mil spec and this thing weighs 22 lbs.
BTW, that spec sheet is for the earlier MKI, mine is a red board MKII Ver5.
$1795.00 in 1983 dollars. This unit is still like new, inside and out. Came with all the docs including the final inspection report, manual and packaging. I might own it but I'm really a care taker for this.

BillWojo

 

[BillWojo]

By the way, I just ran $1795.00 through an inflation calculator and it's about $4600.00. Have you seen the prices of the Reference Series? I think ARC uses a totally different calculator. LOL

BillWojo

 

[E-Stat]

The first two tubes in each stage are 12AX7's and the third tube in each stage is a 6922.

Now I understand your point! It is not that you have an "older SP-8" (since all used the 12AX7) as it is you have an older ARC preamp. My mistake.

Rather unusual tubes to use in a PS but ARC is known for building very stiff PS and I'm in no position to argue with the engineers that designed this.

They now use the 6H30 and 6550 for rectification along with massive amounts of storage.

Have you seen the prices of the Reference Series?

The performance of a REF6 is light years past what they were doing in 1981.

 

[BillWojo]

The performance of a REF6 is light years past what they were doing in 1981.

Did they bring back the musicallity that they seemed to have lost in later units? You know, the toe tappin never want to shut it off factor? That's more important to me than any specs, etc.

Never having heard one of the Reference units I can't comment on them. I have heard a LS15MKI and a LS16MKII and I prefer the SP8MKII myself. I know all of our listening is a personal and subjective thing, so what I prefer may not be what others like. Heck, I'm stuck on antique horns being an Altec fan, but I feel if they are done right they are hard to top.

BillWojo

 

[E-Stat]

Did they bring back the musicallity that they seemed to have lost in later units? You know, the toe tappin never want to shut it off factor? That's more important to me than any specs, etc.

You'd have to determine that for yourself. Others seem to think so.

My SP20 provides a far wider, more dynamic and transparent window to my music than either the SP-6 or SP-9.

 

[Blue Shadow]

Dynamics, transparency and lower noise are some benefits of the newer ARC gear. Easily heard comparing the SP-3a with an SP-9II and of course seeing what @ehoove has to say about the ARC preamps he has used in the past few years. Moving to newer and always loving it.

What Bill is saying is easily heard in that early 3 vs 9 comparison. Both units had the same family sound but the 9 was cleaner and clearer but it lacked a lot of the bloom on the sound that the earlier tube units have. The 3 probably way more than the 6 or 8 preamps. This is what makes the SP-3 a sought after preamp. But then the sound quality, build quality and performance of the rest of the line is what makes most of the ARC preamps desirable units. If someone could clone the AMP modules used in the SS preamps and corresponding power amps they would probably become desirable instead of potential doorstops if a module goes out.

Have you seen the prices of the Reference Series? I think ARC uses a totally different calculator. LOL

I do believe that ARC has a group whose job it is is to infiltrate potential purchasers and evaluate their bank accounts/pockets so they can get top dollar for their gear.

 

[Blue Shadow]

It is interesting that ARC used the first tube in those early units for both channels, Left and Right gain in the first tube then a cathode follower or whatever in both phono and line stage. The manual recommends top quality tubes be used in these two locations, making tube rolling cost half as much as a pre that needs a pair for each location. The SP-3 and apparently the SP-8 only need two top quality tubes and they don't need to match as they are different gain stages and will allow two opportunities to flavor the signal with tube selection.

 

[E-Stat]

It is interesting that ARC used the first tube in those early units for both channels...

They continued to take that approach with the phono section of the SP20 shown at right of photo:

 

[930turbo]

Hi 930,
Thanks for those leads. I can go either way - SS/tube, or phono/line only. I have a variety of phono preamps and SUTs to play with, which may open up options for the next preamp. Am I correct that most of the ARC preamps with phono are MM only, with MC as options?
So many circuits, so little time.
Thanks again!

Among the vintage preamps its only the SP10 and the SP11 can be used w/ both MC & MM Cartridge. In the modern genre the SP20 can also accommodate both MC and MM Cartidge