Recommendation Request for Tube Power Amplifier


I have been using an all solid state system for many years. I hear so much about the "tube sound" experience. I'd like to check it out.The only experience with tube amps that I have comes from these two amps...

One is the Paragon System E Tube Preamp with phono. I bought this new about 1980. It uses six 12ax7 type tubes. I used it quite heavily for a few years. When it developed problems with the volume control, I replaced it with something I can't remember. In storage for a few decades, I pulled it out six months ago, cleaned all contacts, especially the volume pot. Still works!. I have measured this guy quite thoroughly. Phono gain is 43 dB. Distortion from Tape Out is below the noise floor at -95dB. Noise at 60 Hz and multiples is -60dB or better below 0dB recorded level.. Great numbers, even compared to modern preamps. I replaced the old 12AX7 tubes with six matched Genelex Gold Lion tubes.  I'm using this now as a phono preamp with the Koetsu RS and a step up transformer at 20x (Cinemag 1254). The table is a brand new Technics SL-1200G. I really like this sound.

But I'd like to try tube amplification again without spending a fortune.

What tube power amp would be a great match for this system? Years ago, I had a CJ MV75 power amp. I liked the sound, but hated the continual tweaking of the bias, even with brand new tubes. I sold it.

My budget is $3K or less.My system is not too efficient (86 dB sensitivity Revel 105 Bookshelf speakers and a self powered HSU sub, 100Hz xover), so I probably need more than the 3 watt/ch amps I see for some of the less expensive models. How much power do I need? I'm not sure. I've never heard any problems with the Levinson No. 27 or the present Bryston 2.5B cubed, but they both put out 100 W/ch or more. Balanced inputs would be great, but not absolutely necessary.

I consider my present system to sound quite neutral. I worked very hard to get it that way. I'm very pleased with the sound.

I want to exprience that warm tube sound if only to have a change of pace. Or maybe...

Thanks for your help!

128x128Ag insider logo xs@2xkevemaher

Nice preamp. Try to invest in some Siemens or Tele ECC83, it should make it a bit better, and if NOS should last forever. Also a very good match for RWS (I do have it too). I'd just try some other SUTs, but that is more of the personal preference, or acquired taste. Like herbs and spices, like Syrah vs Shiraz...

Your speakers have a low sensitivity, but also unkind impedance curve, which makes for a legitimate double whammy... If you want to drive them properly, something based on KT120 - better yet, KT150 - and at least 100 wpch, would work for sure. ARC is good, but that will costs much more than your budget dictates. Heck, retubing them big monoblocks might cost as much...

I tried to drive Dynaudio S40 with Audiomat, which is 30 wpch and amp known for great current. However, it was not enough to control LF. When pushed, amp lose the control over the LF drivers and they would start farting... If pushed just a bit more, drivers would bottom out and fart out their last fart. Lil' Bel Canto S300iU I had handy sounded "better" than Audiomat... Now, if hooked up to higher sensitivity speakers with tame impedance curve, Audiomat far surpasses Bel Canto. 
Simply, EL34, 6L6, KT60, KT77, even KT88 - based designs are not enough for your speakers. 

When amp and speakers are not properly matched, that distortion is always present. Most of the time, people who are listening at low levels would not even know that something is wrong. However, if they would change the amp, suddenly a mediocre SS would sound noticeably better than a great tube amp... And they would blame the tubes. 

If you want to experience the tubes, I would suggest buying a nice used tube amp and above mentioned (also used) Tannoys - if you can find 15" dual concentric, thats where the magic happens. Then hook up both speakers, changing back and forth for some time. Give the tubes / Tannoys some time before you decide what is better. 

Did I say you have a very nice cartridge?

Depending on the seating distance from the speakers and how loud you listen, I'd look for something that is at least 20wpc.

I have a little 5wpc tube amp and with my 91dB rated speakers at about 8' away and I get plenty of volume for my office system.

http://www.hometheaterengineering.com/splcalculator.html

I recommend Transcendent Sound OTL Tube amps.  Bruce engineers numerous OTL versions, using 300B or more affordable tubes.  And even a 50wpc into 2ohms "bruiser" (that one is not OTL).

They are all kits but for a reasonable fee there are customers on his forum which will assemble for you.

OTL has to be heard to be believed.  Those dern output trannies muck up the sound...

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kevemaher,

A lot of really good recommendations above, I'll add a few from my experience in my system:

(1) Soix's recommendation of a Don Sach's tube amplifier is a really good one. I do not own any of his gear, but I've had several emails back and forth with him, and he's been really helpful....and gave me some really good ideas.

(2) Jasonbourne and Mulvening also brought up a great idea about looking into a modern recreation of the Dynaco amplifiers. I own and can HIGHLY recommend a Tubes4hifi (Bob Latino) VTA ST-120 amplifier; I have mostly NOS tubes in mine. The transformers are monsters, and there is reserve power for days. I have NOS Amperex 6922 and 7308 gold pin signal tubes, KT120 power tubes, and a NOS Philips 5R4GYS rectifier.....definitely pushing more than 70 WPC

A completed amp (they also come in kit form if you are so inclined), is $1,680 without tubes, or $2,040 with a complement of modern 6550 tubes. You can check them out here http://www.tubes4hifi.com/amps.htm

(3) As mentioned above, Brent Jessee is a fount of knowledge on all things tubes, and has a huge collection of new old stock tubes of all types for sale. His website is also loaded with information and research, like this link on pre amp tubes 6922/6DJ8/7308/6N23P/ECC88/etc. 

Best of luck to you!

@piebaldpython, @rodman99999 

Glad to  know that there is at least one other with the Paragon E. rodman999 has a great idea. Roll tubes on the E to create more of that tube sound.

I recently replaced the original  Tungsol 12AX7 tubes (6), made in Hungary who knows when, but before 1980.I installed some brand new Genalex ECC83 Gold Lion tubes, all matched. Listening to these, made me realize that the Tungsol tubes are still making great sound. They are definitively warmer than the Gold Lions. Back in they went.

Can you recommend another brand that would push the tube "warmth" a bit further?

rodman99999 has suggested trying Mullard tubes. Have you tried this tube? The used stock costs approx $100 each.

What has been your experience with tube rolling on the Paragon E?

 

Black Ice (formerly Jolida) are well made great sounding amps, and a relative bargain. Rogue is also well regarded and the Atlas Magnum III is cool. 

@mazian +1

the Rogue ST100 should do the trick

It is a clean and quiet for a tube amp but in triode mode it should give you more of that tube sound you seek.

Old Counterpoint hybrid amps are right in the middle of tube & SS. Plus they can be upgraded to sound better than a lot of amplifiers.

 

 

The Rogue Stereo 100 amp would do the job perfectly with 100 wpc and the choice of triode or ultralinear mode. I have a  Rogue Stereo 90 in which I am currently using Tung Sol KT120 tubes (very hard to get at present), the same as the Stereo100, and it happily drives my Martin Logan Vantage speakers which are 4ohm and drop to 1ohm at times. While the sound is definitely tube it is not the soft tube sound of the 70s and provides transparency, speed and slam in the bass.

I have a Paragon System E as well! When you pop off the cover you will see the quality of the build. Point to point silver solder wiring, etc. All very quality components and the sound reflects it. It is on par with quality gear of today because of it's simplicity and quality of components and labor. 

Rolling tubes nets a nice experience. I can definitely hear differences in manufacture. I mate it with SS amps though and still get what I need- a smooth, warm, full, rich sound that is still dynamic and lively. Bryston is good, I had one and it is reliable to say the least and rather neutral so not a lot of colorization. I have yet to try tube pre/tube power but am hoping to one day however my choice of speaker (Krell Resolution 1) doesn't lend itself to tube power. 

I second Soix's recommendation on a Don Sachs Kt88 amp.  I have one and it will drive your 8 ohm 86db sensitive speakers just fine.  I'd take a look at the link Soix provided and consider buying it.  I wouldn't sell mine for anywhere nearly as low a price as the seller is asking because it will assuredly become a legacy amplifier.  The amp easily compete with ~$10K tube amps and betters a lot of them. 

If I’m you I’d give this Don Sachs amp a serious look. His products receive universally high praise for both sonics and value, and his house sound seems to be a little tube goodness/warmth but no too much while still preserving upper octave detail and offering excellent imaging and voluminous soundstage abilities. Can’t help thinking this sound profile might be right in your wheelhouse.Just another option, and best of luck in your search. Oh yeah, and it’s auto biasing so no more worries about that.

https://www.usaudiomart.com/details/650003930-don-sachs-kootenay-120-amplifier-2700-shipped/

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@kevemaher 

If your speakers really are 86dB, something to consider is that tube power has always been expensive, which is why in the old days high efficiency speakers were common. It was not until the advent of cheap solid state power that a speaker as inefficient as yours could find a market!

So you'll need, in most rooms, at least 100 Watts (200 Watts would be better) and you can see how expensive that gets! So all SETs are not an option- and most vintage amps aren't either, unless your listening room is small or in a bedroom.

So if you are serious about this then getting a set of more efficient speakers would be a very good step.

Otherwise, there are some class D amps that sound very much like an excellent tube amp, on account of having similar distortion spectra to a tube amp. Its the distortion of any amp that is its sonic signature, FWIW.

Before you start, be aware that the original, preferred, and IMHO best tube sound is a single ended triode with highly sensitive speakers.  

There are many people like you that want to try tubes with less sensitive speakers.  In fact, there are more people like you than like me.  So manufacturers have listened and offer a lot of push pull amps that will drive your speakers.  I think it is a compromise, but a good compromise. 

The push pull amp that I have experienced that comes closest to the SET sound is the Decware ZMA (Zen Mystery Amp).  This amp has a huge power supply and simple signal path that makes it shine.  There is a 2 year wait but they are available on the secondary market.

Best of luck,

Jerry

a few recent threads here (I'm for adding tube PREAMP first, then tube AMP, same time or soon thereafter).

https://forum.audiogon.com/discussions/where-to-insert-tubes-while-running-a-luxman-ss-integrated

I feed my vintage tube peamp into my integrated tube amp (rather than just an amp), not using the integrated's features (now) except remote volume and mute.

Consider future changes, where might you use a prior piece? An integrated is more flexible in a second system.

...................................

Efficient speakers make it easier to try tube amps:

price, size, heat, placement options, path of remote beams

and WEIGHT

https://forum.audiogon.com/discussions/can-you-lift-yours

 

 

     When I was doing Dynaco; Joe Curcio was my go-to guy, if I needed advice.

                He's still in the game (AMAZING, after all these years)!

                            So's restored Dynaco gear, when done right.

                              http://www.curcioaudio.com/dynadr_3.htm

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At your budget, looking for a classic tube sound, and needing at least midrange power -- I think restored vintage or vintage inspired amps are the way to go. 

I started out in tube amps with restored Heathkit and Eico amps. They sound wonderful. If you love that wonderful Koetsu sound (especially paired with 12AX7 phono and CineMag 1254 as you've done), this is your kind of sound. 

From there I moved on to Rogue Audio because I wanted more power. This is a common recommendation in your price point (Cronus, Atlas, Stereo 100). They're excellent but will NOT give a classic tube sound, particular in the midband. They excel in bass and dynamics, and respond well to tube rolling -- so you can dial up the sweetness, to a point. It still won't sound like classic tubes. 

And from there now I have modern VAC amps. Very expensive. Amazing blend of classic tube sound and modern high performance hifi. But very expensive. You might find some of their much older models for $3K used, and they can be very good. VAC still services everything they've ever made.

I think the Dynaco recommendation by @jasonbourne52  is a very good one. Someone was making modernized amps / kits from these designs (Bob Latino?), but I'm not sure if they're still around. 

A nicely restored pair of Dynaco MkIII's (60wpc) will work well with those Revel's. Plus the Dyna output trannies are better quality than most of today's iron. I have the Paoli-modded pair. That Paragon E is a keeper! 

    Forgot to mention: whatever diodes/rectifier your power supply uses; they can undoubtedly be improved upon.

    Given you're able/equipped to test for distortion, etc; I infer- you can solder.

                                                    Have fun! 

@kevemaher -

 Sound is smoother, flows easier it seems. 

     Ain't it just great: the electromagnetic musical signal, freely flowing across a vacuum, rather than through semiconductors?

But not the big, enveloping warmth that people glow about. 

     Refer back to my recommendations, as regards the mentioned Brit tubes.   

     Also: my foremost motive, in citing Jessee's site, is that you read his descriptions, observations and opinions, when it comes to the various nations/continents of origin, time frames, OEMs and specific  iteration of a 12AX7 type valve's manufacture.

     One of my prime reasons for trusting him: our hearing must be quite alike.

     You'll still find that information/education invaluable; should you persist in the quest for a tubed amp.

                                              WHY?

                                     Glad you asked!

                      New production tubes just ain't got it!

  Maybe I'll find it with the power amp.

     As mentioned: you've two excellent/transparent/uncolored amps, in the Levinson and Bryston.    Either would convey whatever your particular taste desires.    Even: from session 2 session via a simple tube swap, should your heart be piqued, in that nice tubed preamp.

     Of course: the lid would have to be left off, to facilitate such a practice.

     But: It's been my experience the more air movement the typical component gets around it's innards, the happier it seems, overall.

     My own main amps are Carys, taking four 6550/KT88s per and since NOS Sylvanias, Tung-Sols and GEs supplies have either vanished or become unaffordable, to moi and the Svetlana St Petersburg plant burned down, with all it's equipment: my octet is now Russian Gold Lions.     They were found quite similar in every regard, to my GEs, but for a taste less Bass factor.   

      Quite listenable and why I didn't crack on the brand, in your preamp.

      They shouldn't get in the way, wherever you chose to try rolling better/NOS valves, anywhere in your pre, should you.

                           You didn't skimp on the analog setup.

       Don't lose the fidelity/quality of that source, through your preamp.

                                   DITTO: interconnects/cables!

     If frugal: your budget can easily cover all of the above, sate your taste for a warm/enveloping sound AND (if not already in your lexicon) provide or improve sound staging.

                                        Sorry for the verbosity!

                                             Happy listening!

 

@rodman99999 Thanks for the great advice.

Yes, I have looked at the caps in the PSU and the unit. I normally replace all caps in a vintage audio product. I've done it for all the tuners that have come this way and lately for the two APT model preamps and a couple of turntables. I've been putting it off out of laziness.

Thanks for the tip on the electros that may be in the unit. I will need to look to see if I have any.

I have already noticed a difference in sound compared to the Musical Surroundings phono pre I have. Sound is smoother, flows easier it seems. But not the big, enveloping warmth that people glow about. Maybe I'll find it with the power amp.

Yes, lower powered tube amps are problematical with the speakers I have. I probably need more than 50 W/ch.

I sincerely appreciate the time and effort you spent on your post.

     Nothing (AT ALL) wrong with the above, but: here's another tack, you might consider.

     You already have two excellent amps, that are a better match to your less-than-efficient speakers, than tube power would be.   Even with the powered sub.

      Either would easily prove transparent enough to convey whatever improvements made, in your preamp.

       The Paragon System E (NICE pre, btw) was built with MOSTLY Metalized Mylar caps, which are good (basically) for ever.

       The external power supply is a huge plus, far as noise reduction.

       BUT: if yours has the two, light blue, electrolytic caps; they are over forty years old and could (probably) use replacement.    As well as any electrolytics in the PS.

       Older components can still sound good with aged/weakened electrolytic caps, but: much better, if refreshed.

        Whether you choose to address those or not: why not explore the world of 12AX7s extant, to shape your system's sound, to better suit your aural palette?

        Were you to purchase just one pair of NOS 12AX7/ECC83/5751s: there are three positions per channel, in which you could try them. (great flexibility).

                                                        ie:

         For a warmer presentation: British tubes (ie: Mullard or Brimar).

         Clear as crystal: Telefunken or Seimens.

         Somewhere between those: Bugle Boy, Amperex and some USA (RCA, Sylvania).

         Of course, you'd want to be certain; given their intended purpose (your pre/phono), they were tested for the lowest noise possible.

          Brent Jessee* would be my go-to, far as MY preferential/most trusted source.

          Here's a bit of wisdom, from a popular 6SN7 comparison, that's applicable to any tube circuitry, using multiples of the same tube:

          "One thing became clear based on customer feedback, combining 6SN7 types seems to work better than using all 6SN7s of the same type.

           With so many preamps and amps using this tube, you can end up with
Six 6SN7s per channel.

            It appears combining tubes like the VT-231s as voltage amplifiers and 6SN7Ws or 6SNGTA/GTBs as driver tubes you gain the strengths of all.  Using one type seems to accentuate the tube’s weaknesses."

                           *http://www.audiotubes.com/12ax7.htm

                                (Brent's on vacation until Aug 6)

                                 Have fun and happy listening!

           

 

            

           

           

 

 

@ghdprentice Thanks. I am certainly considering used amps. I've seen a used Rogue 100 here on Audiogon that seems to fit. So far, I've seen great reviews, especially from 10 Audio.

I should add that I'm thinking that this amp will be for my phono system only. I've got the Bryston for the rest..

I too have used solid state amps for nearly four decades, staying away because of the same reasons you state. In retrospect I am sorry that I wasted so much time. My tube amps have autobiasing and slow warm ups to increase tube life. Although in retrospect, biasing is really not that big a deal and need not be done often. I really would not make it a requirement.

 

I am running my speakers (90db efficient) with 70wpc and they will play louder than I can stand without reduced dynamics. Tube amp power is very different from solid state. Because ss are so fast you typically need a lot more power. On the other hand your speakers are not very efficient.

 

I am sure there are folks that will be able to recommend a budget amp for you. But remember… in this price range there are going to be some compromises. How much power do you need? I am not sure… 50wpc?

In the old days tube amps tended to be syrupy and really warm with attenuated detail. So, the word tuby came about. Todays tube amps have converged on detail and are in no longer syrupy. But they have highly detailed bass, great midrange bloom, and have a realism that seldom can be matched in solid state. What you loose is some stirility and slam. The bass with tubes is far more detailed and realistic, but does not tend to give you the exaggerated bass slap that ss amps do.

You might consider used and get a bit higher quality / sounding amp. I think you are in for a treat.