Classic Audio Research Products

[MylesBAstor]

While I have never owned any ARC equipment, I always loved the look of their early gear! Especially the old tube amplifiers. Really felt like were in control of the amplifiers!

[jnr]

Man, I had forgotten how ugly those black and gold SP3s were.

[mep]

The D-79 and D-150 were probably the most industrial looking tube amps ARC ever made. They looked like laboratory instruments. The Ref 75 also has an industrial look about it, but looks way more modern than the D-79 and D-150 (modern industrial?). I owned a D-79 that I purchased as non-working from the original owner. The reason it didn't work was every tube in it was shot and there were a bunch of tubes. I spent days cleaning the amp up (it had sat for years and was filthy inside), replaced some blown fuses, and I put all new tubes in it with all of the small signal tubes being NOS tubes from my private stock. I replaced the output tubes and the regulator tube with brand new current 6550 tubes (SED). After all of that work, I brought the amp back to life slowly with a variac over a two day period in order to allow the caps in the power supply to reform. The amp biased up perfectly and worked perfectly. However, it was not my cup of tea sonically. At the time I owned a Jadis Defy 7 MKII and it sounded much better. The D-79 was a dark sounding amp to me and it just didn't communicate the music to me in a way I expect to hear it.

[MylesBAstor]

The D-79 and D-150 were probably the most industrial looking tube amps ARC ever made. They looked like laboratory instruments. The Ref 75 also has an industrial look about it, but looks way more modern than the D-79 and D-150 (modern industrial?). I owned a D-79 that I purchased as non-working from the original owner. The reason it didn't work was every tube in it was shot and there were a bunch of tubes. I spent days cleaning the amp up (it had sat for years and was filthy inside), replaced some blown fuses, and I put all new tubes in it with all of the small signal tubes being NOS tubes from my private stock. I replaced the output tubes and the regulator tube with brand new current 6550 tubes (SED). After all of that work, I brought the amp back to life slowly with a variac over a two day period in order to allow the caps in the power supply to reform. The amp biased up perfectly and worked perfectly. However, it was not my cup of tea sonically. At the time I owned a Jadis Defy 7 MKII and it sounded much better. The D-79 was a dark sounding amp to me and it just didn't communicate the music to me in a way I expect to hear it.

Yes I loved that industrial look. Nothing said tubes more than that!

What was everyone's favorite vintage ARC tube amplifier (s)? Mine choices are the D250 Servo, the M100 and the Classic 150. I spent a lot of time at a friend and colleagues system with the Classic 150 and ProAc 4s (?) and the sound was terrific. That was until another friend came over and said you have to try these amazing new ICs. Puts them in and the amplifiers blow up. My audiocolleague was so pissed because he had nary an issue with the amplifiers until then. The ICs? The then new vdH carbon ICs. Oops....

[mep]

My first tube amp that I considered a high-end amp was the ARC D-76. I bought this as non-working also. The only problem it had was the owner was clueless on how to set the bias. I set the bias and it worked perfectly. I loved having that amp in my system for years. Never a single issue with it.

[MylesBAstor]

My first tube amp that I considered a high-end amp was the ARC D-76. I bought this as non-working also. The only problem it had was the owner was clueless on how to set the bias. I set the bias and it worked perfectly. I loved having that amp in my system for years. Never a single issue with it.

What is it about tubes and some audiophiles? I had a downstairs neighbor years ago when I lived in the Bronx who had at the time it was purchased, a SOTA system. Timpani 3s, ARC D76, SP3A Van Alstine modded, Linn tt, vdh cartridge, etc. But he had never changed the tubes from the day he bought it (at that point has to be 10 plus years) because someone told him the current tubes weren't as good. Sadly old tubes werent even the real problem with his system's sound. Norm didn't believe in cables and was using zip cord to wire up his system. Now we can argue about cables but I think we can all agree it's not a good thing when the bare ends of the cable are green and rotting!

Same thing with another guy who had Dick Sequerra build some speakers for him (and modded some DH500 to drive his speakers--ahhhhhh!). He had an early Berning TF10 preamplifier (JGH's reference) and ten years later the tubes had never been changed. (the sound was so distorted!) But worst of all, he had these speaker behind folding doors to hide them when not in use. So when I came over, he opened up the door and there were white curtains in front of the speaker. He turned the system and started playing-I kept waiting for him to move the curtains aside--but not dice. But that wasnt the worst thing. The floor was stone and the walls were all hard, reflective surfaces. And we were talking about a megabuck setup, especially for the day!

[tdh888]

Hi ,

Sorry to revive an old thread , just came late for signing up in this forum of your’s Myles . I still have a vintage and a not so new ARC system . I was satisfied w/ my vintage ARC system but when I heard the newer models I was force to sell some of my collection ( SP11 MK2 , D 250 MK 2 servo , Classic 150) . This is what’s left .

[Audioraven]

Nice setup tdh888!

[tdh888]

Thanks for the nice words audio raven

[tdh888]

Hi guys ,

Just an update , I’ve recappped both my D79B’s and replaced the original power cord w/ a 20 amp IEC connector . During the first 4 days of listening after I got them back using a the oem power cord for my ARC REF 610T , I notice the amp has a tighter bass , no bass bloat , more open & less cloudy midrange and extended high frequency. On the 5th day I tried a pair of Shunyata King Cobra CX power cords that I’ve been using w/ my REF 610T . The sound improved a lot more w/ a bigger & more wider soundstage , the amp it seems sounds stronger than their present 75w / ch rating , and it had a more blacker background during silent passages . Because of these upgrades there’s still life w/ these vintage equipment and I’ve been enjoying them for the past 2 weeks .

tdh888

[tdh888]

Additional pictures of the recapped amps

[Bill Hart]

Their big amps scared me, but they were cool looking. I think, at least in the old days, the sweet spot was those 60-70 watt amps. I had several, starting with a Dual 75a (which i still have!), an SP 3-a-1, then eventually upgraded to the SP-10mk ii preamp and Dual 70 mk ii amp. I also had a Classic 60 at one point.
I don't know why I kept the Dual 75a- but I still have the packing, instructions, price sheet, warranty card, etc. though the amp is dormant (and would probably need a cap refresh, though I did buy a full complement of tubes from ARC before the company got sold).
I have heard the later Reference stuff and it sounded good. I eventually migrated away from their products. I did think about another SP 3 for my vintage system, though I thought the black/gold was a little garish back in the day, I dig it now-- totally pimp!
I will post a couple pics later, of the Dual 75a today, as well as an image of a Polaroid (whoa) of my system back in 1975.
I met WZJ back in the '70s- everybody seemed to be afraid of him. I was a simple youth--(emphasis on simple and youth).
I do remember some of the really early stuff, there was a 50 watter (or so) and some of the ones that didn't have faceplates. Electronic Industries? Pelpoe? It's been decades.

[Bill Hart]

Rob- that was my original amp for the Quads (well, I built myself a Dyna ST-70 first, but ante'd up for the ARC as soon as I could afford it-- I was a college student at the time). Not sure I'd just fire it up without a go-over first, although it's not like there are original caps in there-- it was playing fine when I disconnected it from the home theatre system-- I just got tired of all the heat from three tube amps running to play a movie. I'll see if I can find a pic of that as well.

[tdh888]

Hi Bill ,

Had the big amps years ago ( D250 MK2 Servo & the Classic 150 Monoblocks ) they were reliable , the only thing scary w/ them is when it’s time to retube . But their sound/sonics cannot match the delicacy / sweetness/ alluring midrange of the 50-75w/ch amps of ARC . This big amps were all power and control specially the D250 but the Classic 150 sounds / sonically better probably because of its triode configuration.
I’m sure your D75’s sounds sublime .

tdh888

[Bill Hart]

hi tdh888- haven't used the amp in a while, but you guys are encouraging me to run it again. We shall see.

[kcin]

Wow, D79 I first heard one back in maybe 1980ish . Those are really big heavy amps for their power output. Preserving these is an act of love and commitment. I heard this amp along with an SP6 of some type; power a pair of Beveridge speakers along with a Goldmund Studio for source. With the first time I hearing a TBM album I plotzed.

Years later the amp came up for sale and I took it home for an evaluation to run my Acoustat Model IIIs after I foolishly sold my Model X's ( still regret that). Unfortunately, as a poor student at the time I made the wise decision to pass on it and advise a friend who quickly scooped it up.

For some reason the D79c version was a little strident versus the first two versions.

Very nice job, congratulations. I love early ARC.

Here's my completely updated SP 3A-1 ordinarily I like the silver face plates- but on this pre I like the gaudy black and gold. I have a spare silver plate tucked away somewhere.

[Rob]

I like the black n gold, classic. they made three faceplates: B&G like you have and two silver; one is a negative of the other and often called the 'black' faceplate. the really rare ones were full width for rack mounting with openings for mounting screws.

[kcin]

Thanks Rob , I have never seen the negative version of siver.

[tdh888]

Hi ,

Thanks for the nice words . Love your SP3, always wanted to have one specially the one like your’s w/ the black & gold face. I wish it came out w/ the 19” rack mount face but this was only in the silver face model. Just like you I did not like the looks of the SP3-A1 at first that’s why back in the day our first ARC Preamp was the SP6E , I should have chosen the SP3 and most probably it will be still w/ me. The SP6E is long gone .

[Bill Hart]

Purely out of historical interest, here was my system circa 1975-- the speakers were Quad ESLs, the same pair I had restored a couple years ago and now in use in my vintage system. Sorry for the wanky image, it is a photo of an old Polaroid- did those have a focus control??

[tdh888]

I’m sure this setup sounds musical and sweet .

[Bill Hart]

That was more than 40 years ago! It was a good system for its time, I no longer have the preamp- but have the turntable and speakers, both restored, so I could theoretically reassemble that system, but for the SP 3. I preferred the SP-10 mk ii, but it had its own issues. (tube microphonics thru the roof!). The older ARC gear is funky as hell though.

[tdh888]

Hi Bill ,

I still have my arc SP10MK2 . It’s true that you’ll have microphonics if the 6DJ8 installed are noisy . A friend offered 8 NOS Telefunken tubes and I installed it and the SP10 turned into a virtual microphone . I installed Sovtek Low Noise 6922’s and no problem /microphony / noise. They’re very reliable as well .

[Bill Hart]

Same amp, today. At least I dust it: