I'm thinking about a low watt tube amplifier?


I was looking at a small Class A Tube Amp, Finale Audio's F6 Hommage tube amplifier. It runs at 4 watts per channel, which dosn't seem like much but was curious after talking with a friend how amazingly happy he was with the sound of small, low wattage tube amps. My only concern are my Wilson Benesch speakers, which are only 97 db sensitive. I do have a pair or REL's to handle the low end.  I am currently trying out a 20 watt triode Cayin Amp. (CS-55) which has proven to be more than capable of driving my speakers at low to medium volume with alot of room left. I also have a Luxman Mq-3600 triode tube amp which runs at 30 watts, no problem driving the speakers to extreme volume levels. I was thinking of talking with the stereo shop and seeing what his thoughts were, and if he is open to letting me try it out at home? My listening is low-medium volume, condo-living so big volume is restricted to headphones only, classic rock, folk, jazz-but these days the volume is low, even with the headphones, to keep my hearing in tact. I am sensitive to sharp highs and avoid these at all costs.

Anyone have any experience with these tube amps and what are your thoughts, generally, would it be worth the bother.

I don't have any plans on new speakers, but you never know! I have owned horn speakers, and I am not a fan, hearing sensitivity. I am also limited for space so small floor standing speakers or bookshelf considered (down the road).

What small watt tube amp would you recommend? The Pass Labs small amp sounds very good but out of my budget. Budget is $3,000.00 Max. What speakers are you using with your low watt tube amp.?, and what speaker sensitivity are they?

128x128pooch2

I would like to think a small 

amp driving a high sensitivity high impedance speaker is a threat combination.  Small amps are easy to find . Not so with matching speakers.  I do not like horns and big speakers.   I would appreciate suggestions  of a matching combo  

I have a First Watt F5 and an SE 6V6 tube amp.  I built both.  The tube amp sounds considerably better into my Klipsch Forte 1's which are 98db.  OP's 87 db speakers will need more power than a 2 or 3 watt tube amp in my experience.  They will sound too dull and lifeless.  

I really appreciate everyone's input, lots of food for thought. After researching some of the excellent comments, I may come up with some different options on which way to ultimately go. I'm sure I will make a few changes once I have had a chance to sample some of the options discussed. Fortunately its the ride for me, so how and when dosn't really matter. Holding back on pulling the trigger sometimes is difficult but required. Thanks to all. 

@pooch2 Your current speakers will be a disappointment with an amplifier of only 4-5 Watts.

My speakers at home are 98dB and I like more than just 4-5 Watts on them as well, although most of the time that sort of power would be fine.

If you do change out your speakers in favor of something 10dB more efficient (which will mean that your amp need have 1/10th the power to make the same sound pressure), keep in mind that with SETs whatever power they are rated for is not their ’usable’ power. With SETs you really need to not push them past about 20-25% of full power if you want to hear what they are really about. At power levels above that they will start to sound ’dynamic’ due to the excess distortion they will make at those power levels. All that you’ve read about how ’dynamic’ SETs are is the result of people doing exactly that.

Dynamic contrast comes from the signal, not the amp!

After 30 years of studying SETs I remain unconvinced that they offer anything if musical reproduction is your goal. A push-pull amplifier of the same power stands a very good chance of sounding better in every way. There aren’t that many 5 Watt PP amps out there; I built one several years ago just to verify this fact. The additional bandwidth, lower distortion and greater percentage of usable power in a good PP amplifier makes for smoother sound, greater detail and overall more impact.

For your existing speakers I would recommend something with at least 100 Watts in most rooms. The problem here is that tube amplifier power is expensive and 100 Watts is close to the limit where the power bandwidth of the amplifier can be considered high fidelity. As you increase the tube amplifier power, the output transformer imposes bandwidth limitations (this is particularly true of SETs where above 8 Watts is challenging to be considered ’hifi’). With PP amps this limit is around 100 Watts.

There are tube amps that don’t use output transformers and so bandwidth is not limited by how much power they make. These amps are called OTLs (Output TransformerLess). There are also class D amplifiers made now that sound for all the world like a really good tube amplifier. So you do have some options. Low power is fun, but unless your speakers are really efficient or you’re only playing the system in a bedroom or the like, you’ll run into power limitations.

I've really enjoyed my Glow Amp One. It's a Single Ended Tube Amplifier, 5 watts per channel.

Don't know about your speakers, but it does a great job with my older Bose Acoustimass speakers.

 

 

Wilson Benesch Square One Series 2 loudspeaker: Voltage sensitivity: 87dB. Nominal impedance: 6 ohms. Minimum impedance: 4 ohms. Power-handling capacity: 200W, peak unclipped program. Minimum power required: 50W.

If you want to try a flea watt amp, you have to get a very efficient speaker.

I have a 7 watt 300b that sounds great with my Forte IV in my medium sized room. I heard them at the dealer with the Luxman SQ150 and also with the Cornwall which to me was a better match.   I love that Luxman. It’s such a great amp

Luxman SQ-150n is an amazing low power Tube Amp. It's so transparent, neutral (for a tube amp) and clean and more than enough power for my 86db sensitive speakers in a 15x15 room.

It's barely breaking a sweat. I highly recommend.

Added value is an integrated high quality MM/MC phono stage.

We run the Luxman SQ N-150 Integrated tube amp to power the Altec A7-8 VOT speakers. Amp is rated at 10wpc and the speakers are 97db efficientcy. Room is 25 X25 with an 10ft pitched ceiling which gives us 87 db volume at 1/4 power. Great little amp that has received great reviews. 

Go Decware. If not, and you like Pass Labs as you say, get and build two Amp Camp amps. One will give you 8 watts in stereo or more, of course, when the two are run as mono. It is amazing Pass sound, in class A power. Last I saw, they were less than $350 each. Steve Guttenburg calls them “Really really good” and that he was “Massively impressed”.

I appreciate the positive input, I have a very long list of more efficient speakers, which I will continue to try and audition when the opportunity comes up, I am hoping to check out a few shows and sample a few there. 

The small amp available at a reasonable cost peaked my interest in getting this process started. I believe I will try and sample (borrow) a small tube amp, with my existing speakers, before I make the jump and expense of finding a more sensitive speaker I can live with. Once I have done that, and if I find my speakers wanting, I will begin my speaker search and budget for them in earnest. I think I need to try this out in my environment and with my listening conditions to make a realistic evaluation. This to be followed by the small tube amp budget and purchase. I have started the process by selling some of my excess equipment. 

I must admit to be overtaken by my enthusiasm at times for going in a particular direction with my sound system choices. I thought I might find someone here who has been on a similar journey. I am happy with the choices I have for now, and I have to give the process a realistic time line.

Doesn't your friend has speakers he can recommend for the Finale amp?

My guess is that you need to switch speakers and amps. I also think it is unusual with very high efficiency in stand mounts. You may have to go for a floor stander. 

Decware Zen Triode is around $1000 but there's approx 1.5 year waiting list. 

I would agree with Roxy. Your speaker may be rated at 97db (I have read knowledgeable reviewers draw attention to the fact that manufacturers do sometimes exaggerate these numbers). The important question is what does the impedance look like? If you have 90db or above speaker with the right drivers, that is rated 8ohms or above, and keeps there mostly, perhaps only dipping close to 4ohm in a narrow frequency range, you maybe could get away with low power 300b or 2A3 poweramp for the right music. If you listen to a lot of heavy rock or techno type music (and i do because every genre has great music), you will experience low-powered amp reaching its limits quite regularly. A se triode 15 watt such as Art Audio Gill Signature will fair much better - quite surprisingly so. In the zone though, those 2A3 amps are mighty sweet and highly addictive, especially with vinyl.

I'd stick with the Cayin and Luxman amps. Adequate power - and plenty of tube "magic" - contrary to what some claim! Plus enough in reserve to handle music peaks on your 87db speakers!

I believe for a 87 db efficiency you gonna want some more power.  Those just aren't going to wake up until you get some wattage running through them.  I do agree, more watts, is not better necessarily.  I run Decware, 6 watts/channel through Altec Lansing A-7's, 16 ohm.  Don't know the efficiency.  I have seen everything from 95 to 110.  It gets very loud and does everything I need it to do.  For years I ran some JBL 4312's with a Dynaco ST-70 and this was plenty of power.  I believe efficiency is 90 db.  At the end of the day, some leg work will save you grief.  Either get some loaner amps or load up the speakers and take them to the store.  Listening in your own space is the best but listening at the store, you can get some great generalities.  The Altecs are as big as a washer and dryer, you mentioned size restrictions, so probably not an option.  

Don't do it! Maybe you haven't been reading the threads, but the consensus among the know-it-alls is more watts sound better. 

 

(I kid, but too many people believe such ignorance).

Just a thought. A big part of tube sound is their low damping factor. You need way more power than you're using even at reasonable levels if you play music with wide dynamic range. It's only for micro seconds but pianos can give 30 dB peaks and that can upset amps even after the peak is gone. As a guess look into PASS amps. They have low damping factor like tube amps and they make class A like amps that are more powerful than their rating to handle large peaks. The class A amps are class A at their rated power but usually double and go into class B for peaks. But almost all the time you will remain in their class A rating and Pass amps have good power supplies and recover basically instantly from high peaks.

You'll not be happy with an SET and IMHO the push pull design loses much of the "tube magic".

Jerry

They're not cheap, but have you ever heard a CAT JL amp (push-pull)?  

oops.  87 is a different story.  You'll not be happy with an SET and IMHO the push pull design loses much of the "tube magic".

Jerry

I run my Reference 3A de Capos (92 db eff.) with a 4 watt Decware Mini Torii.  Good sound, detailed rich and loud enough in a 12x20 room with the speakers 15ft away

Some random thoughts:

1) Finale F6 is single ended.

2) Finale F6 is rated by manufacturer for 8 ohms only.

3) Most people have no idea what clipping sounds like.

4) Let's try to bring in an expert @atmasphere 

Pass labs are all solid state. Nelson Pass likes to say his amps

sound "Tubey".  They do sound excellent.

Their smallest amp model now is $5,250. Used will be in your budget.

First Watt-by Pass- may be more your cup of tea.

The Altec A-7 is great at low levels and will play with flea power.

Good horns on the correct axis should be fine with all ears.

 

 

 

Flea power is not going to work, but something in the 40 watt range would probably work if you don't insist on head banging levels.  

I don't think a 4 watt amp and your speakers will work very well I thought that 97db didn't sound right as WB speakers are not known as being very efficient. If you don't listen to loudly in a smallish room you can probably get away with a 20 watts or thereabouts as you've already learned. If you want a 4 watt amp get new speakers.

@pooch2 Wrote:

 I'm thinking about a low watt tube amplifier?

Quicksilver Horn mono's would be a great choice. Your ears will thank you! 😎

Mike

http://quicksilveraudio.com/products/horn-mono-amp/

My apologies to everyone the 97 db sensitivity that I noted initially should have been 87 db.

Facten: Wilson Benesch Square 2-87db at 1 meter on axis 2.83V input-6 Ohms nominal, 4 Ohms minimum-power handling 200W peak unclipped-(no minimum given). To my ears these speakers are as detailed using the lower power tube amps.

My speakers have a nominal rating of 99 db/w at 8 ohms.  I have always run low wattage amps, both single-ended triode (Audio Note Kageki) and custom-built pushpull amps.  My current amplifier is a pushpull 5.5 watt per channel amp that has more power than I come close to using, but then again, I don't play my system at very high volume levels.  The better my system has become over the years, the LOWER the volume I tend to play the system at--the sound is rich, exciting, full and engaging at lower volume levels.

larryi: The speakers in use are Wilson Benesch Square 2, nominal impedance is around 6 ohms. I would try to avoid pushing the amp. 

carslbad2: Thanks, nice to hear someone with specific low wattage amp. experience and that your friend is enjoying his Finale Amp. It may be worth a call to the stereo shop.

Just curious, and I may have missed something upon looking at the Wilson Benesch website, but I don’t see any current model 97DB speakers. I only took a look to see what they recommended for amp power and what the speakers' impedance are. That aside, maybe best to pose your question directly to them

97 db per watt at what nominal impedance?  If it is 4 ohms, that would be closer to 94 db per watt equivalent at 8 ohms.  A single efficiency number does not tell the whole story about how easy a speaker is to drive.  Even if 94 db per watt is the more realistic rating, it is possible to be happy with a 4 watt amp.  True, the amp may be pushed beyond its comfort zone at higher volume levels, but, that may be an acceptable compromise if the VAST majority of time the amp performs well.  It is hard to say what any other person would favor when it comes to tradeoffs.  

So my answer is that such an amp might be fine, depending on taste, priorities, specific listening conditions (e.g., room size, distance of listener to speaker, preferred volume level, type of music, etc.).  

4 watts with 97dB speakers is more than enough. i’m running 2 wpc on my 96dB speakers. In addition to music at any level, I’m powering these speakers as the fronts in my HT system listening at theatre levels.

now my 2 wpc amp is called "high current" by the designer (steve deckert) but I think 2 watts is 2 watts.

I have a friend running a finale amp who loves it and I really like the sound of his system.  Should be a significant upgrade over the cayin, both in design and performance.

Jerry

The thread title is a statement and not a question, so no question mark is needed.

As far as the amp is concerned. I would say that it will not prove to have enough power for your speakers. I have speakers that are more efficient, and 8 watts of class A 300b power was not enough in all situations.