To Tube or not to Tube, that is the question

I keep coming back to tubes and if you can budget for them, Octive and  AH Qualiton X200 are great choices. Also Marguiles out of Mexico. 

@bruce19 

Here you go

Brand NEW Amp! Dynaco ST-35 Stereo Tube Amplifier with Mullard Tubes & Cover For Sale - US Audio Mart

What preamp(s) are you using?

Here is a Bottlehead tube line stage preamp kit that interests me.

DeKay

@dekay 

Thanks but the ST35 is also available from Dynakit directly. I learned this when I gave him a call. Seems the business has been paired back to a one man operation from home and he prefers to take orders by phone. Apparently he has not updated the web site, but the owner seems like a very nice fellow. He had one available for me but I was not quite ready to order yet.

@russ69 Thanks for that comment. It kind of helped bring into focus the fact that for me the desire to build something new is at least as much of a driving factor in this as any new sound I will experience. I notice that very frequently the momentum at Audiogon is for buying something new regardless.

Found a ST35 kit in stock, but not familiar with it.

http://www.tubes4hifi.com/ST35.htm

DeKay

If the ACA's work with the F6's you might look into the Elekit 6L6 based single ended amp kit.

It's well reviewed and still available at various vendors for around $900 (link is for details/specs).

Looks like a lot of the amp "kits" are out of stock (including the Dynaco re-pops mentioned).

DeKay

This seems to be a typo, did you mean theST35 is a linear triode?

@bruce19 No.

The feedback is taken from the speaker terminals and then applied to an early point in the amplifier circuit; in this case the cathode of the input tube. In the original ST35 circuit, the input tube was a 7247, which is a dual triode 9-pin signal tube with one section being that of a 12AX7 (the input voltage amplifier) and the other being that of a 12AU7 (for driving the power tubes).

By contrast the ST70 uses a tube that has a pentode input section, which isn't as linear. They were able to get away with using the 7247 in the ST35 since the EL84 power tubes are so much easier to drive than the larger EL34s of the ST70, so less gain was needed.

Clear as mud??

However, the ST70 uses a pentode for this task, where the ST70 uses a much more linear triode.

@atmasphere  This seems to be a typo, did you mean theST35 is a linear triode?

BTW I read your article on amp design paradigms this morning. Good Stuff! I think your thoughts are along the similar lines as Nelson Pass's on this subject, no? Meaning that his Firswatt designs are an exercise in creating tube sound with solid state components. 

I really respect when creator's like yourself willingly and openly share thoughts on design and function. It helps keep this hobby from being a total marketing exercise.

@bruce19,

Look at Quicksilver audio 

Mike

http://quicksilveraudio.com/

@bruce19 

I assume you are in the Tri State Area because you mentioned driving to NJ. I'm in Staten Island if you want to stop by for a listen. Also have a friend nearby that has a SIT3 and some Coincident monobloc's. I tried to send you a PM but couldn't figure it out. 

@bruce19 The advantage this amp has over the ST70 is twofold. First, the output transformers (if they are the same design as the original) have better performance. The second advantage is a bit harder to explain but I'll try:

Like the ST70 this amp uses feedback. A common problem which this amp also has is that the point where the feedback is applied isn't linear, which means that the feedback signal gets distorted before it can do its job of correction. So it adds distortion of its own.

However, the ST70 uses a pentode for this task, where the ST70 uses a much more linear triode. This means the feedback signal is less distorted and so more able to do its job. So overall its a more musical amplifier design since there is less higher ordered harmonic distortion.

@bruce19 

I don't know what year Brimar's I am using I will have to check. I got them from a friend who had a few extra pairs. They are probably around the 50's or so but NOS I love the Sphinx V3 but I happened upon the Orchard Audio tour and like his amp so I bought one. The Rogue is temporary as a preamp. It will stay in my inventory not getting rid of it. Just deciding on a preamp for the Gan FeT. I had the Mini Gan 5 but it was defective and so was the second one he sent to me. I also tried the Gan 400 from Peachtree but the Orchard won out in the end. You have to hear it compared to the others. I also own the Willsenton R8 you mentioned above. Another great amp. I ordered it direct from China Hifi and saved like 400 bucks and still had it in 4 days. They come from a warehouse in California, same as place as if you ordered from Amazon. If you look at my systems page, you can see what I have going on LOL. And it's all a keeper. To me that is

I might add I am leaning towards the Dynakit ST-35 for 3 reasons. It has more power, 17w vs 2w, it's a NJ company and i could drive to get it, no shipping risk, AND it was favorably mention by @atmasphere , which carries a lot of weight with me :-)

@evank Funny I bought a pair of Brimars from Upscale but they were noisy and they gave me all kinds of static about replacing them, so I went back to the JJ's. I think they give a more defined sound which I like, the Brimars sounded more muted to my ears. That is really interesting using the Gan Fet as the power stage on the Sphinx. Since I have one in the form of the MiniGan 5 I may try that one day, but I never thought the hypex units in the Sphinx were lacking. I love its overall sound!

The main speakers I see using with tubes are the two Lii audio full range, open baffles which both have efficiencies in the mid 90spl. Also the Klipsch RP-160s are rated at 96. These Lii speakers in the Caintuck inspired barrel shapes with no crossovers are magnificent, particularly for the money. I do supplement all my speakers in the main system with a trio of Syzygy subs to take care of the deep end.

The Rogue CM is a fine suggestion, if I wasn't focused so much on building my own I would definitely give them a listen. May do so anyway. Same for the Williston and other Chi-Fi. Thanks!

My own research has me looking at Dynakit ST-35,

And this Decware Zentriode kit, https://www.decware.com/newsite/SE84CDIY.htm

I did some parts pricing yesterday and the ST-35 would come in at $875 with tubes and the Decware Zen Triode would be a bout $500

What tubes are you using in the Sphinx. It makes a difference. I am using a Sphinx v3 as a preamp with NOS Brimar 12au7's with an Orchard Audio GaN FeT amp and the sound is exceptional.

Great recommendations above. 

I agree that you should look at China Hifi.  Just be sure to watch the voltage specified with the amp. If you're in North America, you'll want 115/120v.  

I've owned and built all sorts of tube amps.  Willsenton and Doge are amazing amps regardless of the price/country of manufacture.  

To tell you the truth, your Sphinx is getting you 99% there. Tube gear takes a few more bucks to own and operate and you'll need some really nice tube friendly loudspeakers to go with the tube amps. My favorite tube set-ups featured Triangle floorstanding loudspeakers.

I've been quite pleased with my LSA VT-70 from Underwood HiFi, an online retailer. 35 watts/channel with EL34 output tubes (and it will also accept 6550 or KT88 outputs.) They are currently $1,300 plus shipping. 

If you love music and sound definitely experience a true tube amplifier.  A lightly used rogue audio cronus magnum ii should easily be in your range.  

the sound will surpass any current amp you have, the cm sound amazing and have plenty of power, dynamics and authority for your speakers.

you will hear an open, clear dynamic sound.  the sound stage will be large in all directions.  it will be an atmospheric sound, pure in tone and tambre and highly refined and smooth.  vocals and instruments will sound natural and catch your interest, they will seem to float in space.  you need to hear it.  good luck!

My experience is that it takes quite a bit of $$$ before the tube amps really show the magic they're capable of. If you want to stay under $2K, then the best price-to-performance value probably is coming from China nowadays. The offerings from the likes of Willsenton, Muzishare, Cayin, Doge, etc. offer tremendous value for under $2K. 

I have owned Raven Audio Blackhawk MK3, Rogue Audio Cronus Magnum II, Rogers v65-2, VTL IT-85, and a few others. I recently bought a Willsenton R8 for $1500 and was shocked to see that it is better both in terms of SQ and build/finish. You do need to spend an extra $500-700 for better tubes since the stock ones are rubbish. The Willsenton gives you the classic tube sound, and although it lacks the refinement of amps that are, say, over $5k, it is not embarrassed by more highly priced offerings from other vendors.

I bought the Willsenton R8 from Amazon to see what the hype was all about. I was fully expecting to return it within 30 days but that sucker turned out to be too good for the price and I ended up keeping it.

One point to consider is tube amps/integrated won’t have a lot of power so work best with efficient speakers. Uses tube equipment may be your best bet. Of course Rogue makes tube integrateds. Black Ice Audio (formerly Jolida) is a good value. I’m a fan as I own Jolida components.