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Here are some unique John Hogan amps I don’t think have been shown before:
John Hogan SRPP 76/single 6SN7/45 stereo amp. Exclusive green color has given way to the nickname “Green Monster”.
John Hogan SRPP 6SN7/76/300B stereo amp.
John Hogan (Fi Primer?) 6SN7/45/845 stereo amp
John Hogan VTV/Fi Primer hybrid 6SN7/26/VT52 mono amps.
Anyway whats the point of showing off the pictures of those amps?? Everybody already know they're ugly.Say something how they sound and compare and if anybody tried to substitute the "magical transformer "with proper HQ SE transformer and what was the effect. You ,NJohn need no answer. Regards and please, its a question not an inquire for flames.
I am sorry I am not allowed to answer because I heard a John Hogan amp built with the expensive Electroprints and so I know how they compare to the 'magical' opts. Plus I heard relative expensive current production Hammonds too before and after substituting the websters. :)
Unless you know what the specs are for each set of OPTs, you are comparing apples and oranges. It is like comparing different lenses without knowing the apertures and then saying one is better than the other (you may like the results better but is it a better lense?) It depends on lots of things. Also not unlike a low output moving coil cartrige or a step up transformer for that matter. you can take a set of low output cartridges with different internal impedances and run them through a step up transformer designed for a low ohm cartridge and you will find interesting differences. What one prefers may have little to do with 'the better catridge' and could in fact represent a better interface between cartridge and step up transformer. Change the transformer to a higher ohm version from the same manufacture to isolate the variables and the preference would likely change as well to a different cartridge.
You need certain constants to make a real comparison in order to dtermine 'which is better'. < personal preference aside > Also, those Webster OPTs were designed for PP duty and I imagine some of the others that you compared them to were designed for a SE amp.
Not starting up an old debate but it is likely some distortion artifacts that give the Webster their strong characteristic. (Don't view distortion in this case in the worst sense of the word as there is no such thing as a distortion free preamp > amp. Though the Halcro SS amps reportedly have very little measurable distortion) I kn ow very little about amp circuits, but I do know that different tubes want to see a different primary impedance and these Webster OPTs have been used with everything from a 45 (VT-52, 183), 2A3, 300B, 50, PX25, and 845 and the 'sound of the Webster OPTs'endures. I am pretty certain that those OPTs were designed for a particular tube (2A3 I beleive)and perhaps you have discovered something that the engineers did not know...what is the point in paying attention to basic engineering principals.
You did visit John and you heard one of his amps briefly on that visit but it did not strike you fancy enough for you to get interested. You went in other directions.
To me you were missing the boat. Well you know I have my opinions and I myself had not heard anything more appealing in audio except perhaps the WE speakers. To me, you really did not understand the idea of the transformers, what they were capable of, and what John was doing. Nothing wrong with that, you had your own direction.
Now if you did not recognize it immediately then, since you did not give yourself the time and interest and direction to do so, there is no world of explaining it to you.
You might have thought his amp sounded good which you have expressed, but that is not what it is all about. It's about special qualities in the opts.
I agree that not everyone will find the qualities of the opts what they want to work with. Not everyone will go with those particular aesthetic qualities.
Time will tell where the stuff really stands. I am confident now of the outcome.
You can continue to stay on the outside looking in. That's how I see it. Or you can listen/compare and try to ascertain.
My stereos are set-up. My house is organized around the stereos and music. It is now just like art or something that enhances life. It's great and it really adds. I have no interest in the audiophile aspects per se, my interest is in sound.
I lucked out and I've moved on to life. :)
Since you understand OPTs better than I do, can you at the very least can you tell me what is the primary impedance of those OPTs and why is it not problematic to use 2A3, 45, 50, 300B, PX25 and 845 tubes with the same OPT?
I don't understand opts better than you. But I assume that John did and so he was able to utilize them in the various amps you mentioned.
I have no knowledge to be able to defend or complain about it. But I can tell things from a listeners point of view. Maybe someone else on the forum can explain it.
You know I don't live all that far from you that if you ever take a real interest in what I am talking about, you are welcome here. Because I am talking about sound characteristics that appeal to me, and I can point them out in listening comparisons.
I know of at least one audiophile who I respect that John's amps are not to his taste. So I know that various directions are possible.
It'a all about vision and where a person wants to go with sound. And to me, after that, it's all about just how enduring what you pick is.
Hopefully, someone else could chime in if they have any ideas as to the possible impact of running such a wide range of tubes with the same OPTs. I am not questioning the sound of the amps and I am certainly not passing judgement. I am just wondering how that issue is impactful as I have had several amps built and I have always been mindful of the primary impedance, power output and distortion given a specific tube and primary impedance. I am not arguing the virtue of John's amps.
Each of the output tubes you have listed have their own plate resistance. In Class A, a triode tube will give good output power and have low distortion with a load a least 3 times it's plate resistance. The higher the load impedance the lower the output power and the lower the distortion.
A 45 has a plate resistance of about 1650 ohms. Three times that is 4950 ohms. A 300b has a plate resistance of 700 ohms. You see a lot of people using 2500 ohm transformers for the 300b. A 300b will have less output power and lower distortion if it is loaded with a 5000 ohm transformer.
One size does not fit all. But there is some wiggle room.
That was my understanding but I was curious as to the possible effects of using a PP OPT, designed for a 2A3, in a SE circuit using 45s, 2A3s, 50s, 300Bs, PX25 and 845s. John Hogan had used a certain vintage Webster OPT with those various tubes and to good sonic effect according to the people that heard them.
That is what I am trying to say. Armchair philosophy is useless to me.
Bring over your best amps and let's see what's up.
That's the only way to tell what is really going on.
My guess it that your amps are going to have some sound features or aspects that the websters don't have and vice versa. Because different opts are the real reason for different characteristics, and tubes less so.
> > A push-pull transformer will work just fine single ended as long as the power level, especially the DC component in the primary, is so low that you don't saturate the core. In other words, your eight watt transformer can't put out eight watts single ended, but I wouldn't be the least surprised if it worked just fine single ended at two or three watts. < <
I am sure it works fine but I am wondering how it applies to the varies tubes. I think the smaller Webster OPTs were for the PP 2A3.
'Armchair philosophy is useless to me'.
You seem to be under the impression that I am questioning the sonic or musical value of one amp versus another. That is a different area exploration that could be taken up at some point. My question is basic and is rooted in fact.
> > Because different opts are the real reason for different characteristics, and tubes less so < <
Not that this reply is correct but has it ever dawned on you that the different characteristic in tubes that is not apparent could lie in the fact that the OPTS have such a strong characteristic as to not have the resolving power to deliniate the changes in tubes, particularly the input tubes?
There ae many things that go into an amp with the OPTs and the PT being critical along with good power supply design and execution and most certainly a good circuit design and execution.
Again, I am not questioning the sonic merits of John's amps. I heard them and liked what I heard and too many other experienced people, including yourself, have heard them and have been impressed with the sound. I chose not to pursue John's amps because I have my own approach to the hobby. Part of your big interest is John's amps and his ability to draw music out of those Webster OPTs. My interest is researching topologies to gain enough knowledge to be dangerous and then seek enough input from enough people to then have an amp that I am interested in built.
The different characteritics in tubes are very apparent. Even different brands of the same tube are very apparent as per Gordon on the asylum.
You can basically hear everything you need to hear.
But real character of the amp lies in the opts.
To me the websters are like coming home to a sound that I treasure, sound characeristics that are remarkable.
Will what I am saying ever catch on? I doubt it. It might be too much of a mystery to fathom.
In three years of posting on the asylum, I've yet to hear of another set builder who has tried them.
You miss my point and you don't know enough about me to comment on my 'direction' and my understanding of the idea of the transformers. I'll leave it at that.
Sorry but I already knew that you love those amps and "websters" and as a close friend you can't be trusted ;0). Actually I'm quite fond of the utilitarian look of those amps and personally cannot stand chinese -shinny look of all those christmas tree like amps. The one thing which troubles me is that you are using Abbys in your sound assesment and I think its a very poor speaker ; Bleached , colorless ,"midrangey" veiled but again I heard it only on show audition . Regards. L
I don't just have the Abbys. I have numerous speakers and set-ups. I have the Galante Symphonies, two kinds of Omega speakers (super 3's, grande 8), Zhorn with sigma 168, Valencias, huge jbl horns, another real nice vintage Jbl, Speaker lab k-horn, Kloss f200a, and another Kloss speaker, varios klipschs, dx3s, alrtec compression drivers with Edgarhorn, other stuff.
I have the nearfield Abbys which has a different driver. but i heard the other driver the Abbys use and it seems to be a fine driver.
I guess I'm still debating whether I like the single driver like the Abbys or a bigger box.
I deleted the pic by accident. I am also curious about what is going on with those PP OPTs pressed into duty. No one seems to have an answer other than Magic.... The amps sound nice however.
1. “Anyway whats the point of showing off the pictures of those amps??”
Since I am the original poster on this, I am pleased to answer you. I posted some additional pictures of some of the John Hogan amps that I have in response to postings by others, showing their JH amps. I wanted to share pictures for those who are interested in these odd, but unique creations. There are several reasons that pictures of these amps are of interest. It is important to recognize that there are no drawings, schematics, parts lists or specifications for these amps. So we can’t share any of those things with each other. Photos can tell something about the amps, such as what type of transformers are used, proximity of tube sockets and other parts, types of tubes used, owner preferences for specific tube choices, even identification of specific external parts used. Photos of the interiors, of course can tell us even more.
2. “Everybody already know they're ugly.”
That may be your opinion, but others may well disagree with you. To those of us who own these, their outward appearance pleases us for a number of reasons. I am reminded of a friend in my youth who inherited an early 60’s VW bug from one of his sisters. He was very interested in improving the performance of the bug, and kept making mechanical improvements to make it more power and better handling. After a number of years he ended up with a Carrera engine, transmission and brakes. The exterior he left stock in every regard. I have fond memories of riding shotgun when he blew off Corvettes at a stop signal. I believe the term is “Sleeper”. In addition to being “Sleepers”, some of us find great beauty in the simple, raw, industrial look of these and think the emphasis on function rather than appearance is exceptionally cool. That is another reason to show photos, because to some Asylum members, these are a thing of beauty as well as interest.
3. “Say something how they sound and compare and if anybody tried to substitute the "magical transformer "with proper HQ SE transformer and what was the effect.”
That has been done in the past and I am sure there will be more of that in the future. That was not the purpose in this post. I myself am planning on some critical listening to my JH amps over the next few months and making my notes public on this forum.
4. You ,NJohn need no answer.
I am please to answer you , but I believe that Njjohn or any other member has the right to chime in.
5. Regards and please, its a question not an inquire for flames.
Cheers and no flame intended.
I think that I should also say that the increase in posts on John Hogan amps by those of us lucking enough to own them is part of our grieving process. We lost a friend and we all lost an interesting, unique and creative Asylum member. I think the Audio Asylum is a particularly appropriate place to share this kind of information and opinions.
I have just read your comments about tube rolling with the Lector 7TL, and I wonder if you would be willing to discuss any more recent experiences you may have had along these lines.
For instance, I just bought the Lector 7TL MKIII version. Have you heard it? Would you recommend tube rolling with it?
My email address is: firstname.lastname@example.org
for a thoughtful response and I respect your grieving over a lost friend . As a teen i loved a book when the man bought a wreck of Ferrari and build an ugly- duck amphibia car body . He was a historian and sort of modest Eastern- european Indiana Jones . His car was a real sleeper too and I dreamed to have one like that. I wonder if and other PP OPT could do ?? (I imagine that those websters go for a premium now). Regards ,.L
They are still relatively inexpensive. off e-bay for around 100 each but sometimes you can get them cheaper. they come up frequently on ebay.
We tried Conn opts from conn organ amps and we tried the sansui that Korneff used. The conns seemed to me b grade compared to the websters but they have good dimensionality and can be pretty okay. The sansuis don't impress me. also tried dynaco st-70 opts. they have a particular sound and can be used well by some but none of this other stuff seems to approach at all the websters.
I did not realize it had been posted before. Most pics have been of the chassis themselves and not the man's inside work. John was a great man and his kindness and enthusiasm will always be remembered by me. He worked on an amp for me and I spent time listening to several amps in his basement. His amps had the goods, as he was fond of saying.
Hi Rick, I know you have a fondness for the 76. I just brought my srpp 6sn7/76/300b out of the basement, and I was surprised at how good it sounds. As you say, everyone of John's amps (with the webster opts) is unique and a gem.
Out of all your amps though, I think those VT52's with the 26 driver is what I would like. I remember them to have a big California type of sound, and that is where they went. Plus the 26 is my favorite tube.
John made a few gold colored amps among which is a 417a/183 amp which has some remarkable qualities. The 417a is a WE tube, and I don't know if that is the reason it has interesting qualities or its the 183. I plan to post about it someday.
I still need to get the digital camera out. I want to share what I have especially with the people who have some.
I do like 76's as they seem to have a certain sweetness to them, although they give away a bit of punch to the 26.
Over the years I made a habit of sending John various tubes thinking he might enjoy experimenting with them. Of course, I was hoping he would create something great and then I might get him to build something for me. I think it started with 76's and also sent him some 183's, 37's, 417a's, 717A's, 112A's, 10Y's, AZ11's and 50's. I know he found the time to try some of these, and wish he could have had more time to explore the others. So many tubes, so little time.
I guess I was a beneficiary of your generousity with John on the tubes. The reason I say that is that I have a 50 amp from him as well as a 417a/183, and a 717a/45.
They are all one of a kind and remarkable in their own ways.
It was a sudden loss for his family. Really devastating. So there is an unlimited time before we may be able to get some schematics.
I know he pretty much got everything off the internet, and then he improvised some but made few schematics of them.
Is that duct tape spray painted black on the chassis? It looks like it's peeling off the side of the amp with the 6sn7. Were these prototype amps or test use only amplifiers?
It could turn the audio world around to make some ugly amps.
Now when I see something too neat and pretty in audio I have to ask myself why.
It most certainly is not "duct tape spray painted black" on the side of the amp! No sir, it is real honest to gosh black duct tape. John often used this very utilitarian material to patch up openings in the old organ amp chassis he used. Some of his later chassis were a bit more robust with the holes patched with sheet metal. The beauty in John’s amps is not in the eye of the beholder, but in the ears.
Nope, that is pure John Hogan style. He did that to all his amps. He started with gutted organ amps and built them up from there. I think he spary painted one amp faceplate green but that is the only amp of his like that I think. Here is mine. Cheers.
You still have it? I thought you were going to sell it. But if you do you might not be able to replace it. I know it is especially good with Altec.
Hi John, it will be the last thing to go....so if I have to sell it, I will, but I REALLY do not want to do that. Cheers.
I still have the speakers too that I traded that amp for. They probably could be really nice speakers in their own right, but they just fit so well in the room as rear channel speakers in my home theater. I should show you a pic.
It was an interesting day a couple of winters ago to meet you half way between NJ and Detroit.
I had three of those amps but now I have two. It was not possible to pick the two best and send you the third. Not because they sounded so much alike, nor because I would do that. But that each of the 6sn7/26/300b's were slightly different and all were appealing in their own right.
Hi John, I vividly remember that day as well. Man was it cold. I wish we could have hung out for a while. If you ever get around to it, you should replace the SpeakerLab 15" driver with the stock Klipsch K-33 15" driver they use in the Klipschorn. I heard the difference about a year ago when a friend changed his out. We listened to a veriaty of music for an hour then made the swap.....WOW, it is night and day. He ordered the K-33 straight from Klipsch for $130.00 a piece. With buying this business I would not be able to afford better 300B tubes for a while if I can manage to hang on to the amp, but that will be my first purches when I can afford it. Cheers.
I would love to listen to and even buy that "6SN7/45/845" stereo amp.
Enjoy and thanks for the pics,
-- josé k.
"Sentido comun es el menos comun de todos los sentidos"
"Common sense is the least common of all the senses" ... Spanish proverb
Sorry, not for sale. But if you are ever in the Fallbrook, California area, give let me know. Here are some notes on the sound:
"Slightly recessed presentation, neutral or slightly cool sounding, excellent detail, clean & tight bass, detailed mids, clean highs."
The 845's are only run at about 450V. and, like most of John's amps, you can clearly hear differences in tubes. The SuperTNT 845M's work great in this amp, but, of course, RCA's are sweeter and more refined.
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