[DogMeat]

I'm ready to move to a tube amp for a home set-up I'm assembling, want to get input.
Going to run my SACD,(and maybe my open reel Teac), into a nice vintage set of Polks and I'm looking to go tubies.
 
Ideas?
 
 
 
Thanks, folks!

 

[El_Doug]

Without knowing the headphones you plan on using?  No, no ideas

 

[wuwhere]

Are you looking for a speaker amp for your Polks?

 

[songforyou]

And what vintage Polks?  I have a pair of 10Bs (in the garage...no room for them at present) circa 1979-1980.
 
Not too hard to drive, but you will want a tube amp with some grunt if they are like mine (8 ohm, 89 dB). 

 

[DogMeat]

These are the monitor Series 7b's with the Peerless tweeters.
For ElDoug, we're talking speakers here.
I'm newer to the world of tube amps and I am looking for suggestions as to a nice way to drive these. I listen to MUCH classical and jazz music, have MUCH love for all things acoustic. These speakers are excellent, don't really care for the "fat" bass of 10's I've heard,( no disrespect intended there, Songforyou

), I think the stage and clarity of these speakers in a mid-sized room is very nice.
 
Thank you for any suggestions as to specific amps you'd consider!

 

[mulveling]

Price point?
 
I like Rogue's range of tube amps for being built-in-the-USA, and powerful, at very reasonable MSRP prices. It's getting harder to find tube gear with those attributes since Manley had a huge price increase this year (great sounding amps though). Heck even the chinese products are quickly catching up in price, if nothing else. 
 
 

 
Love my Rogue Apollo monoblocks, though those are getting into spendy territory (fortunately this is the high-end subforum). If you're willing to explore the used market, then your options become much richer at any given price point (Manley and VTL for 2, starting at ~$1400, among many many others). Still, if you don't have at least $1K used/$1.6K new, then I'd say don't bother with a tube amp quite yet. 

 

[DogMeat]

LOL!
I don't really have a price point just now, as I am trying to get an idea of what's out there before I will decide on my dollar limitation.
It's worth having ideas on just what the options are before one gets too parsimonious, in my opinion.
 
I can always go back to a year of Ramen, if I find the amp that makes it all worthwhile.....
 
 
 
Thanks for the starter thoughts and your opinions!

 

[Uncle Erik]

First, buy used.

There isn't a whole lot of difference between new and used, so save your money. Don't bother with the cheap Chinese stuff, either. Most of it custs corners and has marginal build quality.

Used, I'd consider the old Dynacos (the ST70 has a cult following), older McIntosh, and I've become a big fan of my old Conrad-Johnson MV52. They don't come up that often, but Conrad-Johnson's EL34-based power amps sound good (there are several models).

 

[DeadEars]

I'm with Uncle Erik on this one.  There are quite a bunch of vintage tube amps that could be good candidates for you.  You should go hang out on some of the Audio Asylum vintage forums for suggestions.  See http://www.audioasylum.com/index.html    My recommendation would be vintage power amps -- you might need a modern preamp/headphone amp or a source with a variable output to work with them
 
Some possible inexpensive vintage choices might include the following: 
* I'm partial to the Eico HF-87 or HF-89 amps which would do a nice job with your Polks and can be found fairly reasonably priced at perhaps $600-800 or so, maybe less.  (see the Yahoo Eico groups for more info).  These are sleepers at the price and can sound outstanding with the Polks.
* Another really good choice for the Polk 7's (great sounding speakers BTW) is the Pilot SA-260 amp, but hard to find in good condition at a reasonable price.  I paid about $600 for mine, and it needed to be restored first before it could be used.  It uses EL34 or 6CA7 output tubes and can sound incredibly nice -- better than many highly regarded brands.
* Some other lesser-known but good vintage brands include Grommes (the rare 260a is superb) or Stromberg Carlson (the AP55 is a powerhouse, and well-regarded even today).
* the Harmon Kardon Citation-II or Citation-V are excellent (see Jim McShane's website for details).  I have two of the Citation-II's that I use as treble amps in one of my home systems.  They will hold their own against modern amps, being very high bandwidth with excellent output transformers.  A restored Citation-II can be found for $1,400-2,000 depending on source.  A basket case might go for $8-900.  Plenty of power for Polk 7B's!
 
If you want to spend a bit more, you can go with the "name" vintage brands like Marantz or McIntosh.  For instance, the very nice-sounding Marantz 8B is a classic EL34 amp, but getting pricey these days, often over $2,500, and IMHO the Pilot SA-260 sounds better.  Or the McIntosh MC-240, at 40 watts per channel or the even nicer sounding MC-225 would be good choices despite their lower power ratings.  McIntosh has re-issue versions of their classic MC-275 amps, which sound really excellent at about $3-4,000 in the used market (see Audiogon.com for examples).
 
A bit more modern, but still vintage, the Conrad Johnson early tube amps such as the one Uncle Erik mentions, or the Premier series are outstanding, but perhaps overkill for your Polk 7B's!  Or maybe not?  I only heard the 7B's in stores back in the days when I sold hi-fi equipment.  But they impressed me then, and I remember them fondly.
 
Unless they've been updated, you WILL need to update and restore any vintage amp.  You should expect to send these to a restorer, like Terry DeWick or Craig Otsby to get them tuned up and made reliable, so figure another $200-600 on top of the purchase price, not including buying NOS tubes.  Most vintage amps will have power supply capacitors that will need to be replaced, and may have resistors that have drifted out of value, or leaky coupling capacitors.  But repairing/replacing these can yield an amplifier that can easily go another 20 years, on top of the 40-50 they've already traveled.  I have a Dynaco Stereo 70 that I built as a kit in 1968 which is still going strong in my daughter's stereo system.  Last year I updated the driver board and re-built the power supply.  Not bad for more than 40 years of continuous service!  Try getting that out of a HDTV?
 
Hope this gives you some ideas...
 
Frank

 

[mulveling]

Ah yes, how could I forget the vintage amps. 
 
I've owned a restored Eico HF-87, Heathkit W5-M, and W4-AM. All 3 have a sweet sound that's bit off neutral, but very euphonic and easy to fall in love with. The W5 has the best sound quality of the group, but the HF-87 too was quite sweet, and the most powerful, with tons of gain to spare. The HF-87 responded like crazy to tube rolling. The W5 will greatly reward a replacement of the 12AU7 drivers - which are the weak points of the amp - with a 6CG7 (so I read - mod required) or 12BH7 (add up the heater current draw; don't exceed the transformer). All three will require some dedication to get restored, if they haven't already. The W4 is a nice amp that can be had restored for ~$450 a pair (cheaper if you DIY), but not quite the level of the other 2. 
 
With the efficiency of the Polks (upper 80's right?), you'll find the vintage tube amps in this range (20-25 W continuous, 70 W peak for the Eico) to be lacking in power, if you like to listen loud (maybe still ok with modern compressed-to-hell recordings, which have no dynamic range to worry about, or in a very small room). Or, you'll just have to learn to be careful with that volume control. My amps were used on 93dB/Watt speakers, and I noticed the benefits from increased power far beyond what these amps could provide.
 
The Rogue Atlas is a very reasonably priced amp with a more modern (clean) tube sound that provides substantially more power, and being a current model it doesn't require restoration. You can swing the sound more to the warm side of neutral by tube rolling - but you can't quite go as far as to make it sound like any of the above vintage amps. The Cronus is the same amp as the Atlas, with a preamp stage built in (better way to go if you don't already have a nice pre). I can recommend either as a starter tube amp - at both their new and used price points. Both amps can be upgraded by the factory to 90 Watts/ch (and IIRC you get a 1 year warranty that way, even if you purchased used).

 

[Thatch]

There is a Polk group where you can get some real advice, and if you gave some I gave up after about post 6 because there wasn't much going on besides leg pulling.
If you want to go vintage I have liked the phone setups in the Fisher Receivers and 7591 integrated amps. That is a start. You can turn the speakers off for phones, pull the phones out, turn on the speakers and I should think run most Polks without a problem. I have a friend that is big into Polks and I think most of his tube gear for driving them is in the 6L6 family of Push Pull, so 30 to 40 watts per channel. And before you sand heads start chuckling over 40 watts per channel the way decibels work is double the watts and get 3 (that is 1,2,3(three) more DBs. So a 350 watts per channel SS amp can only put out about 10 more dbs than a 49 watt per channel tube amp. The most important watt is the first one. Use 100 db SPL speakers and you will use less than a watt for most of your listening. I guess the SPLs on cans work the same. The thing to remember is 1,000 watts is only about 10 bd louder than 100 on the same drivers. Seems like 900 watts would get you more than 10 decibels, but watts and SPLs work on different curves completly and have little in common except they deal with how loud something is (just in different ways all together)
 
                                                  Thatch

 

[songforyou]

Dogmeat,
 
No disrespect taken!  I envy you.  The 7s are 'the' Polks to have.  I purchased when I was a 17 year old knucklehead rocker and more bass meant 'more better.'  And when I bought the 10s, the main competition was Cerwin Vega, so the 10s actually sounded neutral!
 
The advice you are getting here is right on the mark as far I can tell.  If you are set on tubes, I'd would go with an el84, el34 or perhaps a kt88 based amp that puts out 20 to 50ish w/ch.  I have a Mapleshade Scott 222c which you can get for around $1,200 now (I got mine years ago for around $850).  This may appear expensive (extortion to DIYers even), but if you know nothing about restoration or modding (me) it is a great way of acquiring a vintage amp that will put much modern gear to shame.  And it is still relatively inexpensive when compared to modern tube amps.
 
I also own a wonderfully refurbished Dynaco ST-70.  This would work well too.  Glorious mids, but not as detailed or punchy as the Scott.
 
The modern (but now defunct) Sonic Frontiers built a number of good sounding tube amps and preamps.  I did a quick look and there is one KT88 Amp 1 on Audiogon now for $1000 (list $2499).  Their SL1 linestage was a Stereophile recommended component for years (for whatever that's worth).  There are a few on sale there too.  (I'm not connected to the sellers in any way).
 
The Rogue amps/integrateds are also very good.
 
No idea what budget you are thinking, but I drove my 10s with a Pioneer SX-780 I bought at the same time.  You can get something like this for a couple hundred bucks if you just want to get up and running.  The reason I mention this solid-state amp is because of its headphone out.  These amps are getting a lot of attention in the vintage amp thread in the headphone amp forum.
 
Good luck and keep us posted!

 

[Uncle Erik]

I don't know what they're going for now, but I picked up the Conrad-Johnson MV52 for around $700. I've even seen the MV-45 go under $500. As I said, I like their EL34 amps. One thing that's nice about these is that they were built in the 1980s, so the caps and resistors are fairly modern and don't always need replacing.

 

[DogMeat]

WOW!
GREAT input, THANK YOU!
Especially thanks to Uncle Erik- I read much of your posting and you always have valuable things to say.....honoured to have you respond to my thread!
And I SO appreciate the detailed discussions from EVERYBODY, thanks Deadears and Mulveling for zooming in on what works well with the Polks!

 
I have been scanning the vintage market for the Conrad-Johnsons and McIntoshs since they were mentioned here.
The Elco sounds interesting.
 
As I've said, I don't have a specific price range set, so much as a quality and item Name search. I just don't know the names to be looking for in the Hi-Fi tube amp category. I very much enjoy my vintage gear because of the sound and quality of manufacture. It wasn't just 'soldering cheap parts into a box and that was okay as long as sound came out', for some of the better builders out there back then.
Sadly, many of the old Hi-Fi dens have lost their shorts to the cheezy digital market, so over here in Ohio, there's a paucity of places within reach to find used gear and audition it.
The upside is that Ohio is RIFE with garage sales; on any given spring day one might find oneself driving past a set of Utahs or a Maranz sitting on a picnic table with a $45 tag on it. 
May is a big month for that sort of thing.....

 
This is a nice discussion.
Thank you all very much, once again!
 
 
 
 
 

 

[DogMeat]

Got a chance at the MV52.... also a chance at the MV45.Uncle Erik is right on target with his pricing- the 52 is at around $700, the 45 is $475.
Trying to decide which one I should plonk on.
 
I like using vintage gear with vintage gear, try to match within similar production times.
There's something so appealing about the 70's gear sound. Seems to be nice with my music prefs.
I like clarity and stage without overly heavy bass and I have found that the older speakers do that nicely.
Matching a nice amp to them is just a better way to go.