[Texbychoice]

Currently all Solid State.  Thinking about trying a tube amp.  Would have to be compatible with solid state pre-amp.  Speakers are rated 87dB sensitivity, 60W continuous, 120W peak.  Have a separately driven sub woofer.  Small listening room. 

DIY approach would be fine as budget is under $800.  Any suggestions for a good performing quality amp?

[FullRangeMan]

Currently all Solid State.  Thinking about trying a tube amp.  Would have to be compatible with solid state pre-amp.  Speakers are rated 87dB sensitivity, 60W continuous, 120W peak.  Have a separately driven sub woofer.  Small listening room. 

DIY approach would be fine as budget is under $800.  Any suggestions for a good performing quality amp?

No suggestions with this low efficiency speakers, at only 87dB forget a tube amp, you will need a muscular SolidState amp or Class D.

Using a tube amp in these adverse conditions will have a lot of problems, change your speaker to a 100dB 8Ω and benigh minimum impedance. Sorry for the bad news.

[JakeJ]

I disagree.  A 60 Watt push-pull tube amp will work fine with his speakers as long as he doesn't crank up AC/DC to concert levels.  Just my .02.

I personally have been mating tube preamps to SS power amps with great success for years.  SS pre to tube amp I haven't really attempted this but a couple of times with limited sucess.

In general one should look at impedances of preamps to power amps, a general rule of thumb is for the load (amp) input impedance to be at least 10 times higher than the source (preamp) output impedance to provide a suitably flat frequency response.  If the amp has an input impedance of 100K ohms then the preamp should have an output impedance of ~10K ohms (this is not carved in stone but a guideline).

We can provide brand and model selections if you tell us what preamp you plan to use and if you know the specs list those as well.  Suggestions are much easier and better if some more info is shared.

[opnly bafld]

Have you ever checked to see what levels (dBs) you listen at?

I often use solid state preamps with tube amps and have used speakers as low as 85 dB 1w/1m with very good results.
Never owned a tube amp over 40 watts and never listen at concert levels.

[rotarius]

Agree with others, tube amp can work for your speakers since you have a small listening room.  However, finding a 60 watter for 800 is not easy.  I used to buy high power ss amps all the time until I bought a restored Kenwood integrated with power meters and saw I rarely exceeded 16 watts with 88db speakers. 

[Texbychoice]

I know that speaker 87 dB rating is low, but have power meters that indicate 10W peak at sound levels right at the threshold of being too loud.  M505 amp rated at 105 W at 8 ohm has been able to drive any speaker ever owned way beyond comfortable listening. 

Pioneer C-21 pre amp is rated at 50Kohm, 1V/450 ohm (rated) output impedance.  So is that going to be a problem finding a matching tube amp?

Don't know listening level dB, but definitely not concert level.

[JakeJ]

Took a quick sweep of the used market and nothing fits your criteria.  A few amps available for $500-$800 but all are 35 W/ch or less.  You may need to reconsider your budget.

The only decent kit that has the power is the VTA ST120 but that is $1199 in kit form with tubes.

[rotarius]

[quote author=Texbychoice link=topic=173384.msg1831747#msg1831747 date=16053704
Pioneer C-21 pre amp is rated at 50Kohm, 1V/450 ohm (rated) output impedance.  So is that going to be a problem finding a matching tube amp?

Don't know listening level dB, but definitely not concert level.
[/quote]
No problem.  1v is rated output not max output.
Look for a Jolida 502 or 3502 used.  You may find one close to your budget.  I have a 3502 with claritycap upgrade and it sounds great.

[opnly bafld]

Pioneer C-21 pre amp is rated at 50Kohm, 1V/450 ohm (rated) output impedance. 
So is that going to be a problem finding a matching tube amp?

As stated, no problem with the C-21

ST70 EL34 kit is $899 + shipping
http://www.tubes4hifi.com/bob.htm#ST70

Should be able to find something used in the $700 - 900 range if you take your time and look.

[SET Man]

Hey!

    If you need more than 60wpc to make your speaker come alive in an average room size then I think you need to get a new pair of speaker.

    Don't get hung up on just the sensitivity, another important thing to consider when pairing speaker to tube amp is impedance. Tube amp like flat and benign impedance speaker. I used to have Magnepan 1.5 with 85dB driven by 18wpc SET amp in small room and I could play more than loud enough, my usual listening level is 85-88dB peak at listening chair. My SET monoblock were fine driving the Maggie 1.5 because their impedance is a very flat 4 ohm.  By the way what speaker you do have now?

  Anyway, at your budget of $800. I'd look at used amp, maybe something with KT88. Although, some older tube amps might need to be recaps soon, but if you can DIY it that can save you a lot of money.

   Well, good luck and keep us posted.
Buddy

[FullRangeMan]

Usualy a 50/60W tube amp use eight 6550 tubes, this is a lot of tubes, a lot of heat, electric bill, bias etc what is suíted tô him is a 200W Class D, no heat, small, or a efficient set of speakers.

[Tyson]

Small listening room means you only need 20 to 30 watts.

[JakeJ]

LOL, some great suggestions in this thread.  Welcome to AudioCircle were the members delight in spending other members money!  Although hopefully we haven't discouraged you with too many choices.

So I believe this will work just fine if you take your time to find an amp.  When you narrow it down come back and ask the gang what they think about your choice.  You should be able to find an amp with at least 40 Watts per channel that fits your budget, 60 Watts would be better.  So you are looking for amps that run EL34, KT77 (Euro designation for the EL34), KT88, and/or 6550.  EL84, 6L6, and 6V6 amps will likely not provide enough power to drive your speakers.  I think you will like the sound quality of a tube amp.

EDIT:
The US designation is 6CA7 and Euro is KT77 & EL34.  My bad, sorry.

[HT cOz]

Try OddWatt http://oddwattaudio.com/owproducts.html

[opnly bafld]

Small listening room means you only need 20 to 30 watts.

I agree with Tyson (unless you listen at what I would call very loud levels 95+).

A few years back I successfully paired a triode connected KT88 amp (@20 watts) with 85 dB speakers in a medium sized room.

[Texbychoice]

Already have more Solid State Watts than can be used, so Class D is out.  My power meters tell me even approaching 10W peak is hearing loss level.  Tube amp Watts ratings are not different that SS Watts ratings are they?   Plan to keep my SS amp so could use it or a tube amp. 

Keep coming back to the ST-70 VTA kit or doing my own resurrection of an original unit.  Maybe nothing more than tugs of nostalgia.  Thanks for all the input.  No decision yet. 

[opnly bafld]

Already have more Solid State Watts than can be used, so Class D is out. 

The operator uses the volume control to determine amount of power getting to the speakers.
Quality over quantity is my motto, but I have used 100 watt amps with speakers rated for 5 watts continuous and 15w max.

[ssglx]

   My power meters tell me even approaching 10W peak is hearing loss level.   

I'm going to repeat myself to again present the case for fewer, quality watts. My ANK EL84 tube amp with 17.5 watts gives me very satisfying volume even with my 81 db monitors along with good strong bass. $1100 in kit form.

My "big" amp is a 24 watt Monarchy SM70 Pro and I never clip it in my smallish (~10x14) room.

I have many years of experience with this system (Monarchy/KEF/Soliloquy), and several other systems before that. I don't agree with the view that you need higher wattage to be supremely satisfied (as I am), and locking yourself out of these other alternatives.

[Texbychoice]

I'm going to repeat myself to again present the case for fewer, quality watts. My ANK EL84 tube amp with 17.5 watts gives me very satisfying volume even with my 81 db monitors along with good strong bass. $1100 in kit form.

My "big" amp is a 24 watt Monarchy SM70 Pro and I never clip it in my smallish (~10x14) room.

I have many years of experience with this system (Monarchy/KEF/Soliloquy), and several other systems before that. I don't agree with the view that you need higher wattage to be supremely satisfied (as I am), and locking yourself out of these other alternatives.

Agree quality is the key.  Current SS Amp was acquired when had larger listening room and also driving a subwoofer.  Now smaller room and sub has it's own amp.  Just pulled the trigger on a reasonably priced ST-70.  Original transformers, VTA board, double original capacitor size, upgraded RCA and speaker connections.  Will report after hookup.

[opnly bafld]

Just pulled the trigger on a reasonably priced ST-70.  Original transformers, VTA board, double original capacitor size, upgraded RCA and speaker connections.  Will report after hookup.