thanks. I will have to write the mods to figure out how to be changed from Member to Industry Expert. Are any of us really experts?
Tube pre amplifiers
- Thread starter retired farmer
- Start date
I would say that the ML 33H Amp has an almost god like resolving power and articulation in the 20hz up to 3-400hz range and is very Good for basically all music with instruments and tonal weight in this way.
So a tube preamp that equals the ayre K1xe in this way I would think is …
Ear Yohino 912!
Especially IF it is tuberolled with
National Matsushita PCC88 Revalve Kit
This is a known way to make the 912 into an absolute beast, especially considering the 33H most loves quality: that Insane articulation in the deep fundamentals .so put on the list. But Get a tube kit too!!
The other tube preamps already mentioned HERE Are Good to, of course..
But They will not match the Ear 912’s output transformers for Dynamics, and pure resolving power in the med and deep bass.
And that IS where the 33H is king, as well.
Happy hunting.
In my experience rebuilding hundreds of pieces of vintage tube gear, including some of the top tube preamps of the day, building hundreds of my own preamps for sale, and now producing my final design as I at least semi-retire, small signal tubes should be avoided. The larger the plate, the more relaxed the sound, yet with full detail. Tubes like the 12a*7, 6922 variants, etc... can sound decent, but they pale in comparison to a top notch preamp using larger octal tubes like the 6SN7, or DHTs if done correctly. If you want the best tube preamp, find a balanced one that is based on tubes with large plates like the 6SN7. My 2 cents, take it or leave it.
We Are excluding First Sound Presence Pre’s from this of course?
Those do well justice to the 6922 family.
Not much that makes a 6SN7 beat a 6dj8 IF we pit it against a FSP pre…
I think its more about circuit and powersupply
But Again, milage..
Hi
I knew when I posted that I would get in trouble
I am looking at that pre online. I see banks of lytics and small signal tubes and coupling caps. Based on decades of experience I don't have to listen to that preamp to know what that sounds like, no matter how well you build it. It sounds like a small signal tube, done very well I am sure. I will give them credit for using an OA2 to regulate the plate supply for 150V. That will isolate the plate supply and give current regulation. We do the same with a larger OD3, but the power supply I use ahead of that is completely different. They are using the best coupling caps they can find. Great. They appear to be using a series stepped attenuator built with Holcos or other good resistors. Cool. I prefer a shunt where there is only one naked foil resistor in the signal path on each channel regardless of volume setting. Perhaps they are using a shunt, but it appears to be series. If you use a very good quality large plate tube, and you eliminate all coupling caps by using a custom wound transformer, use a completely different power supply architecture with no electrolytic caps, etc... you get a completely different sort of sound that I much prefer after years of experimentation. It is great that you like that preamp and I am sure it sounds very good. It doesn't sound like a large plate tube in a completely different sort of circuit. I prefer that sound. It doesn't mean that the First Sound is not a great preamp, and that you cannot love it. I know which sort of topology and tube type I prefer to listen to though and was providing that advice to the OP. I do stand by what I posted. Hey, what do I know.... I would never own a solid state amp. I can build one, but I always listen to tubes and I own tube friendly speakers. Let's just say that my push pull mono 300b amps are in AN Gaku-On territory. That is my way. That doesn't mean that all the people who like high powered solid state amps to go with inefficient speakers are wrong. It just means we have different tastes, that's all.
Again, I am sure the preamp you note is a very nice unit. I am also sure it has a different sound than the topology I prefer. I would recommend the OP audition a top quality preamp of both sorts before making a decision.
Ah..Hi
I knew when I posted that I would get in trouble
If you use a very good quality large plate tube, and you eliminate all coupling caps by using a custom wound transformer, use a completely different power supply architecture with no electrolytic caps, etc... you get a completely different sort of sound that I much prefer after years of experimentation. It is great that you like that preamp and I am sure it sounds very good. It doesn't sound like a large plate tube in a completely different sort of circuit. I prefer that sound. It doesn't mean that the First Sound is not a great preamp, and that you cannot love it. I know which sort of topology and tube type I prefer to listen to though and was providing that advice to the OP. I do stand by what I posted. Hey, what do I know.... I would never own a solid state amp. I can build one, but I always listen to tubes and I own tube friendly speakers. Let's just say that my push pull mono 300b amps are in AN Gaku-On territory. That is my way. That doesn't mean that all the people who like high powered solid state amps to go with inefficient speakers are wrong. It just means we have different tastes, that's all.
Again, I am sure the preamp you note is a very nice unit. I am also sure it has a different sound than the topology I prefer. I would recommend the OP audition a top quality preamp of both sorts before making a decision.
Well. So the Beatles have a song called Blackbird.
Lovely song, and it must be one of Paul McCartney most loved tunes. WHEN the Beatles split and a new band formes, Paul called it Wings.
Black Bird a Raven. Poetic!
Indeed the preamp you Are mentioning seems very Nice.
My bid for egg in the nest:
Tung Sol Jan CTL 6SN7GT aka VT 231 end of ww2 era. I would guess on this you agree.
This tube also go by nickname Blackbird, IF we imagine ..
The Raven, It looks very Good indeed.
Hmm. I agree, that one really looks nice!
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Hi
Actually, I have a whole collection of "Holy Grail' 6SN7 types including the venerable TS round plates, the Sylvania bad boys, national union, ken rad, and many I have forgotten. I sold most of them off because to my ear the Linlai E-6SN7 and the Shuguang WE6SN7plus (which is FINALLY back in production) are equally good or better than old stock 6SN7 tubes. But the fun thing about both the Raven and the Blackbirds is they use classic tube types (6SN7, KT88, 300b) that have wonderful modern production examples to buy, and all the NOS beauties that folks can roll in there as well. The only tubes that aren't modern production are the damper diodes and the VR tubes, but there are literally tons of them for sale at under $10 per tube, so it isn't an issue.
Anyway, I had no intention of hijacking this thread, just that the Raven is pretty much what the OP is looking for and I hope he can hear one. It is fully balanced, and will drive a 600 ohm load because it is transformer coupled. So it doesn't care about low impedance SS amps. It is not a classic tube sound, but rather very open and extended, which would suit his amps I think. Again, my 2 cents. No one is right or wrong, just things to look at.
Frame grid triodes like the 6922 and 6DJ8 are very linear but aren't designed for audio so tend to have trouble with microphonics.
If you are considering a balanced preamp, you might want to know about the balanced standard, also known as AES48.
The balanced line standard helps keep interconnect cables as neutral as possible and its for this reason (since microphone cables from 70 years ago didn't use exotic materials) that the Golden Age of hifi was possible.
Of course this has a direct effect on the quality of sound you get in your home. But we can put this another way: if you have ever heard a difference between cables when auditioning them, that difference is a bad thing no matter how good the better cable was. The reason is next year the manufacturer of that cable will have a better one and if he doesn't, someone else will. This means that no matter how good that better cable was/is, its not right- there are always trade-offs in the sound.
You can get off that cable game if your equipment supports AES48.
The balanced line standard, AES48 uses a system where the ground (shield) of the cable is not used for anything related to the signal- IOW ground is ignored by the system. This prevents the shield and insulation from having an effect on the sound of the cable. For the same reason, it also prevents ground loop noise.
Very little of 'high end audio' balanced preamps support the balanced line standard despite being balanced. That is why you read so much controversy in high end audio as to whether balanced lines are actually better or not. Here's the truth of the matter: if the equipment used supports the balanced line standard (AES48) then the balanced lines will sound as good as a cable can sound, so yes, better than any RCA cable.
So when you are looking for a balanced preamp this is something you might want to think about, since some cables can be quite expensive (and can lose their value rapidly after purchase)! There are fully differential balanced line tube preamps that support AES48.
BTW there are only 3 methods of supporting AES48:
1) using an output transformer, since they can be isolated from ground. Distortion is introduced due to the hysteresis loop involved with any transformer.
2) there are specialized solid state circuits (these days, usually using an Integrated circuit ) that allows the output driving the balanced line to 'float' so doesn't reference ground.
3) the third (patented) system uses a direct-coupled Circlotron output. The direct-coupling has several obvious advantages. Oddly, despite being the newer system, this one has been in use considerably longer in high end audio than the other two.
I am highly recommend the KR Audio P135. 45 circuit with solid state power supply with balanced inputs/ outputs and remote control.
I use it with 46 globes and the sound with my magnepan 20.1is VAST.
6SN7 is a nice circuit but it can't touch a 45/46, in my opinion.
I use it with 46 globes and the sound with my magnepan 20.1is VAST.
6SN7 is a nice circuit but it can't touch a 45/46, in my opinion.
The 45 is indeed a great tube. I use some in my Pacific 2 DAC, and have also used 46 tubes with adapters. The problem with a commercial preamp using them is there are no good modern production for any reasonable cost. They are certainly available, but $750 a pair and up, and you need 4 of them for a true balanced circuit that has two channels. So your tube cost, even at OEM prices is $1500 to start. Makes for a pricey preamp. Your preamp uses a jFET for the gain stage and a single 45 per channel. They are using a transformer so that is most likely how they are getting xlr out and the same on the xlr input (or they are converting xlr to rca with SS first). If there is only a single 45 on each channel, then it is a single ended circuit that is being converted to balanced on the output. I am sure it sounds great, and the reviews are wonderful, but it is not the same approach. To do fully balanced tube should require 4 x 45 tubes, two per channel. I have thought about building our circuit that way for fun as I have a couple of quads of 45 tubes, but as I said, it gets pretty pricey for a production preamp when you need a quad of 45 tubes to start. Anyway, not dissing your preamp and I am sure it sounds wonderful and glad you love it. I do assure you that the 6SN7 throws a soundstage that is 3 -4 feet outside the speaker boundaries and floor to ceiling (12 ft in my room), and on some recordings it will come out to almost 180 degrees, and depth of course. The same circuit built with 45 tubes would do the same thing, but it would probably have a little more of the acid-etched clarity the 45 gives you. Certainly would be fun to try!
BTW, your preamp is very reasonably priced for what it is!
Yes, and that only really matters if you are using a DAC with a really good XLR output. If your inputs are single ended, then the sonic benefits of fully balanced, while still there, are not as great. I am sure it is still a great preamp, and I really liked the Positive Feedback review where he compared it to other REALLY good preamps. Your preamp held its own against some stiff competition. Once things get to that level it is more about what you prefer. They are all good.
I built single ended preamps for years and they sounded very good indeed. I just got hooked on a fully balanced system from DAC to speaker terminals in the past couple of years with this 300b project and I can't go back.... Except when I use my turntable as the source. Again, no rights or wrongs, just what we like.
Thanks. I've seen similar levels stated for SUTs which strikes me as odd since the levels are so much lower.
I'm using a single ended DHT DAC running a pair of 45 mesh (see photo as I thought you might find its construction interesting) which I eventually plan to replace with a Pacific 2 once funds allow.
Very interesting DAC and very fairly priced. I use DC-DC conversion quite a bit for regulated filament supplies. What I cannot tell from the photo on their site is how they are coupling the DHT output. I don't see a coupling cap or transformer, and of course they don't say. I am sure it is a cathode follower output and the tubes are run at very low plate voltages ala Lampi, but not sure how they are coupling to the rca jack. Do you know? Anyway, that is a very reasonable price for what I am sure is a very good sounding DAC. There are a lot of choices in the $5,000-$10,000 price point and I would certainly like to hear that one vs. say the top end May DAC, which I have heard. The May is very good for the money. The Pacific 2 kills it, but the price difference is HUGE. As I said, there are many very good DACs in that $5,000-$10,000 price range.
Ah... digging around I read that he uses coupling caps.... guess I will have to hunt around in that photo to see them. Still, looks like a good price for what is a probably a very nice DAC.
There is a little yellow tantalum capacitor in the signal path. I haven't yet compared my acuhorn to a Pacific 2, although I plan to via my local dealer, however whilst I'm sure the Lampy will be better I'd be interested to hear how much better. The Acuhorn is really fantastic.
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For that price I am sure it is! I just have a Lampi because I am an OEM and I know the distributor, and I buy them used.. so they become at least remotely affordable. I will say that once you get used to one it is hard to listen to anything else. They have this sort of "organic" sound. You can hear the resonances in the bodies of instruments more than with most other DACs, and that is what I value in a stereo. It is what my amps and preamp do. Of course, the Lampis have that walk in sound stage as well, but most competent DACs can do that. Anyway, if I were only spending $5-7K on a DAC I would certainly look at yours, especially if he had a fully balanced one with DHT output stage.
He does.
Acuhorn R2R XT
Founded in 2003, presented high sensitivity single driver speakers, with highly recommended Acuhorn Nero125. The best matched series of OTL tube amplifiers Acuhorn S2 and series of Mosfet single ended amplifiers Mono and Stereo. Next introduced the rare puristic design of one 'Big Tube' tube...
www.acuhorn.pl
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