[jrebman]

For those who aren't familiar with Bruce Rozenblit and Transcendent Sound, he is usually best known for his OTL amps as well as the Grounded Grid preamp, and other things -- most of which are available in kit form as well as assembled.  Anyway, I saw that he is coming out with a new, non-OTL single ended amp with a cathode follower topology:

http://www.transcendentsound.com/cathodefollower.htm

Anticipated kit price is in the $800 - $900 range and puts out 3.5 watts.

I corresponded with him this morning to see if he has any more details than are currently posted on the web site and he replied that he will be making an announcement with more details in about a week.

So, if you're interested, watch this space for an update when it is available.

-- Jim

[JLM]

I've only heard his pre-amp.  Nice, but tube syrupy.

[Ed Schilling]

Jeff,
The GG is the least syrupy tube pre amp in the world. I (and I'm sure anyone else who has heard one) have no idea what you could possibly mean. I have both the SE OTL and the GG and "syrupy" is not a word that describes either....not even close. And I bet Bruce would be very surprised to hear someone call the GG "tube syrupy". You are confused here, I think. It's not likely you actually heard a Transcendent Sound  Grounded Grid Pre amp. And if it was "tube syrupy" then I suspect it was broken. "Very solid state sounding" would be much closer I think.

BTW....I too have been in touch with Bruce about his new amp. He said that when the new transformers are in and the thing is "ready for prime time" he's going to send me the prototype to play with. I'll be reporting on my forum what I think.

Ed

[Wind Chaser]

What does syrup sound like?

I have two different varieties of 100% pure maple syrup in the house and I can't for the life of me hear anything no matter how close I hold to my ear.  Am I going deaf, or is my syrup just too pure?

[Rocket_Ronny]

Syrupy HA !!!

When Wind Chaser got his Iverson Electro Research strain gauge cartridge mounted on the Magnapan arm and Oracle Delphi, driving Acoustat Model 2's I told Wind that it sounded syrupy.

S U R U  P Y !!!! He said in disgust. Well wouldn't you, he paid $5,000.00 Can. for the EK1, and that was back in the early 80's. It was called the most expensive cartridge at the time by some.

So he peeled of the the brand new Ricky Lee Jones album, I mean just taken out of the shrink wrap and played for the first time new, off of the sticky Oracle mat and went upstairs. What in the world is psycho Johnny up to now. You never know what is next with Wind.

He comes down again and puts the record back on the Oracle, only it is totally covered with some of  the best maple syrup around.

Turning on the Oracle he gives me the evil eye stare and says, SYRUPY HUH ! I Will show you what syrupy sounds like as he starts to lower the arm. True story.

Rocket_It always pays to be honest, even if it is syrupy_Ronny

P.S. Turns out the syrupy problem was the vertical tracking angle of the Maggy arm was way too high, killing the highs and giving everything a thick sound. Once dialed in the EK1 kills. So much so that I became addicted and would whip over to Johnny's for a fix on my way to my girlfriends house. Needless to say I was late many times and she gave me the boot eventually as well. Chalk it up to audio 101. But I did end up with my very own EK1 not long later. Enjoyed it very much.

[Bwanagreg]

Nice to have another low cost SET option. I wonder how it will compare to the Decware amps.

Any idea what power tube this uses? I can't tell by looking at the picture.

Also, can I get a side of sausage with it? 

[floobydust]

 Well, nowhere does it mention SET on their website... but the output tube looks more like a beam power tube, albeit new manufacture somewhere east of here. Seems simple enough for 3-4 watts output single-ended, should be fine for starters, and as they mention, could a real experimenter's delight for those so inclined.  I think everyone should have access to kit-form audio and this looks to represents a nice offering and a good price.

 The text also seems to imply that the amp smooths out bad digital sound, not sure how that works, or how nobody else has been clever enough in the past 8 or so decades, to design a cost-effective cathode follower that works. Maybe marketing flare... ?

 Regards, KM

[andrewbee]

single-ended, class A transformer coupled amp.
The tube compliment is a 6550/KT88 for the output and a 12BH7 and 12AX7 for the front end. 
The 12BH7 can be replaced with a 12AU7 with no circuit modifications required. 
Using a 12AU7 will reduce power output by about 1/2 watt.

The bottom end is down 0.5 dB at 20 Hz.  The cathode follower output has a very low output impedance of just over one ohm so the bass is tight and clean.   No mushy, boomy bass here.  Since the output impedance is so low, no feedback is required. 
 
The treble is down 0.5 dB at 60 kHz.  The amp is therefore, very fast and lets delicate high frequency transients through.  The wide bandwidth gives the amp its OTL like quality.

Harmonic distortion is 1% at one watt, rising to just under 2% at 10 kHz just before clipping.  This is very linear performance for an amp with no feedback showing that the cathode follower drive is an ideal way to go.  No bias adjustments are required.  Tubes do not have to be matched but they should be from the same manufacturer to balance performance between channels.

[floobydust]

 Sounds like a solid design, thanks... and nice choice of tubes as well. The output stage appears to be strapped-triode based on 3.5-watts. correct? Do the OPTs have a UL tape for the screen?

 Regards, KM

[jrebman]

You beat me to it... again .

I've been keeping my eyes out for a nice SE KT-88 amp.  Just this morning found the SimpleSE from tubelab.com, and may buy a PC board from them.

-- Jim

Sounds like a solid design, thanks... and nice choice of tubes as well. The output stage appears to be strapped-triode based on 3.5-watts. correct? Do the OPTs have a UL tape for the screen?

[andrewbee]

The output stage appears to be strapped-triode based on 3.5-watts. correct? Do the OPTs have a UL tape for the screen?

I would think the outputs are triode strapped.

No idea about the UL tap, depends on what Bruce uses I suppose. Maybe he will buy an off the shelf unit with them or maybe have a special opt manufactured. He does speak of the amp as being one that is good for experimenters, lots of space and an Aluminium chassis so maybe UL taps. Drop him a line over on his website and ask, I think it would be a nice addition if the tap (or taps) were available, however I personally doubt it will have them.

[mgalusha]

Having owned several of Bruce's products and both his books, my money is that he'll use an off the shelf OPT but then again I could be wrong.

[doorman]

I'm with Ed on this one! My GG pre is about as "non-tubey" sounding as I'm ever likely to afford! It could well be that the unit Jeff heard had an issue(s)
                                                                                Don

[TerryO]

I'm with Ed on this one! My GG pre is about as "non-tubey" sounding as I'm ever likely to afford! It could well be that the unit Jeff heard had an issue(s)
                                                                                Don

Don,

Was that your GG preamp that we heard up on "the Mountain" this Summer?

It was the first and only time that I ever heard one, which spent a few hours connected to my 4780 chipamp. In "that" combination driving a variety of speakers (fullrange and 2-way) I would certainly not describe the sound as syrupy for any that I heard.

OTOH, I like the "honkiness that All horns exhibit", prefer vinyl over iPods and have never heard " a correctly designed line array" that impressed me enough to want one.
VMMV

Best Regards,
TerryO

[doorman]

Hi Terry. Yup, that was (is) my pre. I've not heard it sound bad paired with anything. I recall it working real well with the chip-amp. The only "syrup" I remember was at breakfast!
                                                                          Don

[TerryO]

Hi Terry. Yup, that was (is) my pre. I've not heard it sound bad paired with anything. I recall it working real well with the chip-amp. The only "syrup" I remember was at breakfast!
                                                                          Don

Don,
I thought that it sounded great with the chipamp, and that's a fact! I've always wanted to build one, and when I get rich maybe I will. I can't imagine needing anything more than the GG offers and I've heard systems that contained several 100,000 dollars in gear. While I "think" the megabucks systems sounded better, it wasn't by much. I believe that's the surprising part of Audio; that intelligent (yet inexpensive) choices can get you so very, very close to the best, for a comparatively minuscule amount of money. Of course, those who are into DIY probably already know this.

A while back, on another forum, I bragged that I had the best "Under $100 System" in the World. I was quickly disabused of that notion by not only Dave (Planet 10), but several others as well. These guys form a pretty rough crowd 

Best Regards,
TerryO

[JLM]

Just to clarify a bit.  I heard the grounded grid pre-amp (assembled by the owner, who I don't know that well, but is not a world reknowned electrical guru) at a DecFest years ago.  So maybe it wasn't built right, I dunno.  Compared to the Decware stuff (which I find neutral to the point of being nearly sterile) it had a good amount of output, but sounded noticably thick and warm, like stereotypical tube sound.  He was a proud papa and it generated quite a bit of interest. 

As a point of reference, I'm a long way from being a tubehead.  I've not had good luck with reliability of tube gear, SETs lack power to properly drive my choosen speakers, and bigger tube amp designs typically bloat bass on my speakers.  Only 45s are seductive enough to interest me, but I'm leery of what the tube "magic" is doing to the overall sound and I wouldn't give up my speakers for it.  I know that makes me an oddball among the single driver fan club, but I rather like being an individual.

[Ed Schilling]

Jeff,
Your clarity is still just simply wrong. I repeat, the GG is not "typical" of "tube gear" and compared to anything even Decware it is not "thick and warm". Now I can't say what you heard but I can say what is "reality". I have built 3 of them and there is very little way to "mess up" but it's possible. Your comments are in direct opposition to what anybody else is likely to think or has ever been said about the GG. And make absolutely no sense to those who "know better". Had your comment been about many other preamps (tube) except the GG then almost everyone would be agreeing with you instead of scratching their heads.

Now, about this...."As a point of reference, I'm a long way from being a tubehead.  I've not had good luck with reliability of tube gear, SETs lack power to properly drive my choosen speakers, and bigger tube amp designs typically bloat bass on my speakers."



That's what happens to  single drivers when placed in a TL (and eq.ed for "deep bass). And something I knew decades ago. And no amount of "math" can fix it. I personally would prefer that my speakers work with ALL types of amps (that are decent) and the fact that yours apparently don't work with low or high power tube gear is very telling of the design. But hey, if bloated overblown bass is what sounds good to you (you being a "generic" term, not directed at you, Jeff) then that's all that counts. We've been down this road before. The regions below 60hz are much better dealt with by using a sub WITH SINGLE DRIVER SPEAKERS. But I could care less if anyone agrees.....but consider this....I have TRUE flat response to below 30 Hz if I want it, I can and do use a 1 1/2 watt OTL amp and I don't have "bloat" problems with any tube amp that is not "bloated itself". And the outputs I can achieve with 3 or more watts are insane. Who cares about "deep bass" if you can't play AC/DC at live levels. Bass is easy. SPL is not and just as important....even for little girls with guitars....especially if they happen to be Mary Huff, for instance. Reliability? Ha. That is not an issue with properly built , well designed equipment whether tube or SS. As a matter of fact it's much easier to damage SS than tube gear and there are mass market tube amps > 50 years old still working fine except for maybe some leaky caps in them.

Just my opinion, mind you.

Ed

[JLM]

There is a lot I like about you Ed, but we seem to cross paths on several audio points and you don't seem to let up. 

I don't know why I heard what I did of the Transcendent Sound pre-amp.  It was maybe an hour audition under audiofest (uncontrolled, unscientific) conditions.  It was years ago, so I can't tell you what speakers, etc. were used with it.  I don't even know if it was built strictly according to factory specifications or not.  No axe to grind, just reporting what I heard.

The faulty tube amp I mentioned was shipped directly to me after the manufacturer worked on it, as a loaner from a third party.  No amount of tube swapping or change of settings helped alievate the intermitent shorting/crackling.  The times it worked, it sounded wonderful, and amazingly powerful for 12 wpc, but again it bloated the bass severely (the speakers were run without any compensation).  All this was observed by other knowledgable audiophiles/tube lovers.  I'll not mention names, but the company is one you should be familiar with.  Again, no axe to grind, in fact I wanted to like tubes, just has never worked out.

Some of your comments above are obviously "misplaced".  We've all read your opinions of "math", single driver TL, The Horns, little girls with acoustic guitars versus the importance "insane" spls and hard rock.  Lets just move on.

[Ed Schilling]

Jeff,
My comments (most) are not aimed directly at you but are "in general". That said...your opinion of the GG is still in direct opposition to what is reality. 10% opinion 90 % fact on this one. As to the tube amp comments.....you simply have not enough experience (obviously) with tube gear. The fact you got a bad amp means absolutely nothing and is insignificant statistically speaking.

Again, I'm sorry that you don't understand that if all tube gear even high power stuff "makes your speakers sound bloated" then the problem lies not with the amplifier. This is, in my humble opinion a DIRECT consequence of the design. And "compensation" will only make this situation worse.

"We've all read your opinions of "math", single driver TL, The Horns, little girls with acoustic guitars versus the importance "insane" spls and hard rock. "

Well, Jeff, apparently reading is not understanding. My comments are based on almost 25 years now of building TL's and  almost (now) 18 years building single driver speakers. No "new math" has changed the behavior or "sound" of them or the way they work. Whether a fellow uses "new math" to design one or does it by trial and error the effect and end result will be the same. And it is a bad result for a single driver. And Jeff, I'm sorry but high SPL is important. I had a guest by yesterday (he is buying a pair, now) who brought by just one piece of vinyl.....he said " if they can play this at the levels you claim ( I had warned him he'd not understand) then i'm sold". The record was Nirvana....the one with the kid in the water on the cover. The system was the GG, the SE OTL, (1 1/2 watts), Hagerman Phono Stage.

The peaks hovered around 100 dB. He was dumbfounded. And said " well, I had no idea that you were not kidding, especially after walking in and seeing how tiny they are". I explained that the OTL was only 1 1/2 watts and to play them really loud I'd need to hook up the F1.

So we did....and played "Enter Sandman" (see, others besides me do "rock out"). So we did. This resulted in peaks higher that 105 dB.  So then we walked in to my TV room and I cut the TV system (100 watts) on with Metallica. We covered our ears (really) and I let her rip.....I drove them past distortion and into "banging the VC's". The level was in excess of 115 dB....it sounded HORRIBLE but I let them run like that UNTIL I COULD SMELL THE DRIVERS. Not a joke. I then cut them down. No damage at all. You could still smell them several minutes later. They are undamaged.

Do I care if this is important to everyone? NO. But it was important to me and him. Nirvana NEEDS to be played with authority. A system that can't "is a little girl  system". Sorry, but that's the way it is or at least the way I see it.....and I'll say it every time I think it needed.

All single driver speakers are NOT the same and they do NOT all have the same "limitations". Using a Cube My system will play MUCH louder and cleaner (at those volumes for sure) and have deeper, tighter bass  than any "MLTL". It's a fraction of the size and tubes don't make the system "bloated" and SS doesn't make it "sterile". This is not an accident, it is "by design".

Again, I fooled around with your type speaker using a single driver almost 20 years ago. Nothing has changed.

I agree, let's move on.

Ed