Hello Guys,

I am getting more and more curious about the "Tube Thing" and am wanting to get into it myself.

I'll start by describing my system briefly.  For more detail, check my profile.  I have 1981 Cornwalls, with original crossvers, presently powered by a Marantz SR7300 HT Receiver.  The plan is to first get a tube power amp, and eventually a tube preamp as well.  I have two subs, which are used primarily for home theater.  In stereo mode, they're usually turned down pretty low, if not off.  I listen to CDs and records equally.  I'm currently using a cheap DVD player for CDs and DVDs, connected digitally to the Marantz receiver.  However, it's transport creates a constant audible "whir / ringing" noise, so I'm looking to replace it.  Probably with an Onkyo DV-SP406 for starters, and eventually add a used tube DAC for CD playback.  For records, I have a Denon DP-23F turntable with Shure M110HE cartridge that I'm happy with.

I find that my system really doesn't "BAD" so to speak, it just sounds kinda 2D sometimes.  I'm looking for something to kind of "open up" the sound, so to speak; make it sound more 3D.  It seems a bit flat sometimes.  However, I don't want that overly muddy "old tube" sound.  I do still want to retain clarity, without it getting too tubby, as I have heard some tube amps do.  For example, my old Heathkit- that was pretty tubby.

I have always heard good things about Audio Research especially that they tend to still retain good clarity.  I have found a D-51 amp online which is from the 70s, however it was serviced by AR 3 years ago.  The seller claims some caps where changed, as well as tubes.  He also provided serial number, which can be verified against AR records, so I have no reason not to believe him.  He's asking $1,150, which is no small amount of money for me, however it has been recently serviced, and ought to be good to go for quite a while.  Also, most AR tube amps seem to go for more than that.  It uses 6550s in push-pull to make 50 wpc.  The seller has good feedback with previous audio related gear.  he even has the original box and manual, which certainly shows attention to detail for something this old.  If it helps anyone, a schematic can be found here.

Anyone have any opinions of this amp? Or any other recommendations?  I listen to mostly classic rock / folk, i.e. Pink Floyd, Tom Waits, Joan Baez ELO, Supertramp, and Poco (currently playing "A Good Feeling to Know" on LP as I type).  I also play some classical - mostly pipe organ, but some symphonic.  Very little electronic, no rap.  I don't listen to any modern rock /pop, but I do like some of the more energetic classic rock like Def Leppard, AC/DC, etc, so some volume is required, as well as good dynamic punch for rock.  Something that's too "squishy" definitely won't do.  On the other hand, I certainly wouldn't want an extremely sterile sound, but I wouldn't think tube gear would do that.  This AR is at the upper end of my spending limit, so any recommendations couldn't be any more than this.  As I have mentioned, there are other things to attend to.  Whatever I get, I would like it to be of such value / demand that if I don't like it, I can still sell it and not take a beating.  So, something that's well known and well thought of would be good.

Well, enough of my rambling!  I hope that helps more than it confuses!  If anyone has any thoughts, I would definitely appreciate it.

Thanks a lot!

-Jon

EDIT: Perhaps another option?  Sonic Frontiers Power 1 SE 

 I haven't listened to a D-51 since the late 1970s, but this was one of the better sounding ARC amps of that era. In that era, this would be an amp that people would move UP to from the Dynacos and Fishers and McIntosh amps of the time. I don't know how that price compares to other examples of this amp, but getting that level of sound quality for $1200 bux is a great deal on an absolute basis. i.e. there aren't a lot of great amps you can purchase for $1200. Good luck with it if you go that way! Sure like to hear a report if you do!

Hello Mdeneen,

Thanks for your advice.  Your words certainlly sound encouraging.  So far, it's number 1 on my very short list of considerations.  I think I should at least send the guy an e-mail to see if he still has it.

Thanks,

Jon 

Hello,

Small update.  I heard back from the seller.  He does still have it.  He says most tubes were replaced except the rectifier tube.  Also, most caps were replaced.  He doesn't remember exactly which ones.  However, he offered to check with ARC after Christmas, which I thought was nice.  He claims it cost about $1000 to repair!  It does have 17 tubes in it, and quite a bit of electrolytics, plus ARC's labor is $80 / hour, so I suppose it could be feasible.  Still, that's quite an investment into an amplifier to go and sell it three years later!

Here's a page on the ARC Database with pics and info.

He said he is going to list it onebay on January 3rd if it doesn't sell before that, so I guess I have until then to make a decision.  Unless of course someone buys it before that.  I don't intend to wait anywhere that long to decide.  Any thoughts with the additional info?  I am really thinking I should go on this.  It looks like a beefy, well made amp that's in good shape for a reasonable price.  Probably not too many around like this I'm guessing.

As usual, your thoughts would be appreciated!

Thanks,

-Jon

I'd suggest getting a full list of what was done to the amp. 3 years is a long time so any tube replacement could be meaningless. Most manuals for tube amps will suggest output tubes be replaced every 2 or 3 years depending on usage and if the seller purchased replacement tubes from ARC that alone could of been a sizeable percentage of the money he paid most OEM's really markup there replacement tubes. Realize that this is a 30 something year old amplifier and unless completely overhauled it could have issues at anytime. If the list of parts replaced is pretty extensive then you should be fine but I'd surely get varification of what was done.  

                                                                                                                    Craig

Jon,

Thanks for the ARC webpage. I have a D79 (label does not say A,B or C) which has a similar compliment of tubes and in 1986 a new set of replacement tubes was around $400.00. So now it would probably be alot more and a large cost as previously written will be the cost of new tubes.  I used the D79 on a pair of Dahlquist DQ-10s and they never sounded better on any other amplifier. I use the Jubscalas now and only keep the D79 around because the DQ-10s are in the closet. Good Luck with your purchase. Audio Research Corp makes a good product, as long as it sounds good to you.

Wrinkles  

ARC puts out an outstanding line of fine sounding tube amps when they are running well. They operate toward the ragged edge of the engineering limits - biased hot and really getting the max out of the tubes. I know four friends in town who have owned ARC tube amps, and three have moved on to safer, more reliable units from different manufacturers. The fourth replaces his tubes every one to two years, and still has trouble keeping it fully turn key operational. BTW, he is a great tech at the largest repair audio place in town. He just loves their sound, so he puts up with the $$$ and reliability issues. It costs him a lot less money than most people...

Merry Christmas everyone!

The ad for the amp mentions only 150 hours on the tubes, which would suggest they have a lot of life left in them.  However, I do share your concern over it's age and overall operating condition.  I didn't really think that deeply into it before.  This is why I've learned to wait before making a purchasing decision.  Too many impulse buys gone wrong.  I've also been finding some reviews suggesting it's not the most dependable amp out there.

The above is causing me to strongly consider that Sonic Frontiers amp.  It's about the same price ($1200) and was made around 1998 (20 years newer) and has been well reviewed.

Thoughts?

-Jon

Well it's over.  I've finally picked an amp.  The funniest part of it was that after all this consideration of the Audio Research and Sonic Frontiers amps, I ended not buying either of them!  I ended up buying a V.T.L. ST-85 . 

This one even has Mullard EL-34s (what vintage, I don't know).  I did a search on A'gon for tube amps from $900-1300, and up came a rather considerable list.  I saw the VTL, and knew the name, and remembered good things.  Some research found both a favorable Stereophile, as well as many very favorable reviews on Audioreview.com.  I liked that it was made in 2003, and had good reviews, and seemed reasonably priced.  I also really liked that it had optional triode mode available, which is what I'm guessing I'll use most of the time.  In tetrode mode, it's rated at 85 wpc at 4 ohms and about 60 wpc at 8 ohms.  I haven't been able to find out the rating in triode.  Perhaps a call to VTL will solve that.

I e-mailed the seller yesterday (a day after it was listed), asking if was available, and letting him know I was interested in it.  He said yes, and also dropped the price to $1000 including paypal, plus shipping.  Basically taking off about $140.  I thought that was surprising, especially given that the amp was only up one day.  However, I certainly didn't complain.   So, it's on it's way.  I'll start a new thread with a review and some pics, once I get it and spend some time with it.

Thanks,

Jon

It will be interesting to see what you have to say about the amp. I'd imagine the amp is coming with Mullard reissue EL34's (glorified Russian EL34's with the Mullard name stenciled on them) not real vintage Mullard EL34's but regardless reasonably good modern EL34's...I read that he is including 3 extra tubes so if the 7 tubes were vintage Mullards the tubes would be worth more then the amp.

                                                                                                                                                                           Craig

Hey Craig,

That's good to know about the Mullards.  It sounds like that's what they are most likely.  Unfortunately, the 3 extras really don't do me any good, as you're supposed to use a matched quad, right?  Seems like the chances of finding a fourth tube to match those three is remote.  The seller brought it to UPS on Saturday, however it's going all the way from AZ to PA, so it's going to take a while.

I'll be sure to report my observations when I get it.

-Jon

I believe the amp has full bias controls for each tube ?.. If so matched quads are not absolutely required although you wouldn't want wildly mismatched tubes.......but just to be clear when purchasing output tubes always buy matched quads since ordering singles will net you the worst tubes a tube seller has on his shelves..... the ones he could not match...

                                                                                                                                                                        Craig                       

Hello Craig,

That's helpful to know about the individual bias pots.  That's good to know about the matched tubes.  I would not have known vendors would do that.  I always buy my tubes matched, but that gives extra incentive!

Once again, you provide useful insight.  I may have more questions when my amp arrives.  Hope you don't mind!

Thanks for sharing!

-Jon