A japanese bok ISBN4-416-19209-6 (363 pages, printed 1992, Koichi Shishido) describes the following tube amps:
*DA30 8W single end, interstage transformer
*811A 8W single-end, interstage transformer
*801A 8W single end, interstage transformer
*826 8W single end, interstage transformer
*RCA-808 12W single end, interstage transformer
*RCA-800 10W single end, interstage transformer
*8012A single end, interstage transformer
*826 8W single end
*RCA800 28W PP, interstage transformer
*RCA830B 15W single end, interstage transformer
*UV-838 35W single end, interstage transformer
*805 50W single end
*6N7 7W PP
*6L6 PP
*4D32 20W single end
*preamp with 6DJ8
*DA30 8W single end, interstage transformer
*811A 8W single-end, interstage transformer
*801A 8W single end, interstage transformer
*826 8W single end, interstage transformer
*RCA-808 12W single end, interstage transformer
*RCA-800 10W single end, interstage transformer
*8012A single end, interstage transformer
*826 8W single end
*RCA800 28W PP, interstage transformer
*RCA830B 15W single end, interstage transformer
*UV-838 35W single end, interstage transformer
*805 50W single end
*6N7 7W PP
*6L6 PP
*4D32 20W single end
*preamp with 6DJ8
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Better is nebulous . . .
Please define the playing field first.
More output power
Lower distortion
Square Wave response
Rock music, chamber orchestra, female torch singer, or an acoustic guitar
Sounds better in your Hi Fi / Stereo system in your room
Sounds better in another Hi Fi / Stereo system and location
And . . . The genius of the designers and builders to make both the Loftin-White amplifiers, and the Interstage transformer amplifiers the best they can be; when compared to less perfect Loftin-White and Interstage designs.
Etc.
Which exact models of Loftin-White amplifier(s) and which models of Interstage amplifier(s)?
By the way, in reference to your question about auto bias:
Interstage transformer amplifiers can have auto-bias; and Interstage transformer amplifiers can have fixed bias.
What a big playing field, and so far, generally Loftin-White refers to a single ended design.
Now, enter the Push Pull amplifier field . . . Reset, and start the discussion all over again.
As farmer Brown once said: "My cows are outstanding in their fields".
Different farmers have different fields.
To be serious and friendly, I hope you enjoy picking a specific amplifier design (or design your own), build it, and Enjoy listening to it.
. . . All that is possible for so many who read and write on the Tubes / Valves threads.
Please define the playing field first.
More output power
Lower distortion
Square Wave response
Rock music, chamber orchestra, female torch singer, or an acoustic guitar
Sounds better in your Hi Fi / Stereo system in your room
Sounds better in another Hi Fi / Stereo system and location
And . . . The genius of the designers and builders to make both the Loftin-White amplifiers, and the Interstage transformer amplifiers the best they can be; when compared to less perfect Loftin-White and Interstage designs.
Etc.
Which exact models of Loftin-White amplifier(s) and which models of Interstage amplifier(s)?
By the way, in reference to your question about auto bias:
Interstage transformer amplifiers can have auto-bias; and Interstage transformer amplifiers can have fixed bias.
What a big playing field, and so far, generally Loftin-White refers to a single ended design.
Now, enter the Push Pull amplifier field . . . Reset, and start the discussion all over again.
As farmer Brown once said: "My cows are outstanding in their fields".
Different farmers have different fields.
To be serious and friendly, I hope you enjoy picking a specific amplifier design (or design your own), build it, and Enjoy listening to it.
. . . All that is possible for so many who read and write on the Tubes / Valves threads.
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I remember Shishido's amplifier designs appeared in Sound Practices.
Some of them used Interstage transformers with quiescent DC plate current in the primary, and quiescent control grid DC current in the secondary.
His genius idea was to connect the primary and secondary current directions to be in the opposite direction, so that the two quiescent magnetic fields would cancel each other.
Primary milliamp x Turns = Secondary milliamp x Turns.
The cancelled magnetic fields allowed the interstage transformer to use interleaved laminations.
No Air Gap, just interleaved laminations.
I hope that helps some to understand a part of his genius.
I did not ever hear Shishido's amplifiers.
But I did hear Sakuma-sans amplifiers at one of the VSACs at Silverdale, WA.
Some of them used Interstage transformers with quiescent DC plate current in the primary, and quiescent control grid DC current in the secondary.
His genius idea was to connect the primary and secondary current directions to be in the opposite direction, so that the two quiescent magnetic fields would cancel each other.
Primary milliamp x Turns = Secondary milliamp x Turns.
The cancelled magnetic fields allowed the interstage transformer to use interleaved laminations.
No Air Gap, just interleaved laminations.
I hope that helps some to understand a part of his genius.
I did not ever hear Shishido's amplifiers.
But I did hear Sakuma-sans amplifiers at one of the VSACs at Silverdale, WA.
Ah yes that’s it. I actually own a copy.
Attachments
A small guitar amp with a 300B output tube. Output transformer Tango U-808.
What happens when the amplifier overdrive (distortion spectrum)in this three cases.
1. Driver tube 12BH7. Interstage transformer #10487
2. Loftin-White. Driver tube 12BH7
3. Driver 12BH7 SRPP, capacitor coupling.
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tjrneld,
So "Better" is judged by what the guitar amplifier sounds like, when it is driven into clipping?
Right?
for the following:
Interstage coupling (with, or without, auto-biasing?)
Direct coupling with auto-biasing
Capacitor coupling (with, or without, auto-biasing?)
Which tube is being driven into clipping?
12BH7, 300B, or both?
I admit, I do not have a good answer your earlier questions.
Perhaps a good simulation program of the three amplifiers will answer the question.
Or perhaps only if 3 different amplifier configurations are built, can the question be answered.
Might anybody in the Instruments & Amps threads be able to answer your question (that is one of the thread categories that is for guitar amplifiers).
I was not aware that Shishido designed guitar amplifiers.
This is the Valves / Tubes threads. Often the discussion here is for good musical reproduction and good fidelity for Hi Fi and Stereo tube amplifier playback systems.
Just my opinions.
So "Better" is judged by what the guitar amplifier sounds like, when it is driven into clipping?
Right?
for the following:
Interstage coupling (with, or without, auto-biasing?)
Direct coupling with auto-biasing
Capacitor coupling (with, or without, auto-biasing?)
Which tube is being driven into clipping?
12BH7, 300B, or both?
I admit, I do not have a good answer your earlier questions.
Perhaps a good simulation program of the three amplifiers will answer the question.
Or perhaps only if 3 different amplifier configurations are built, can the question be answered.
Might anybody in the Instruments & Amps threads be able to answer your question (that is one of the thread categories that is for guitar amplifiers).
I was not aware that Shishido designed guitar amplifiers.
This is the Valves / Tubes threads. Often the discussion here is for good musical reproduction and good fidelity for Hi Fi and Stereo tube amplifier playback systems.
Just my opinions.
Anyone have a PDF of this? I bought a copy from the Japanese bookstore in New York City about 20 years ago. I scanned it and sent it to someone here on DIYAudio.
I lost my hard copy and asked the guy I sent the scan to to send it to me. I never heard back despite many attempts.
I’m not trying to deny the estate of royalties inasmuch as I’ve paid full price for my copy. A lot of my tube related stuff was stolen by the drug addict movers when I became disabled and downsized to a smaller home.
Peace,
Rick
EMK2,
Sakuma-san brought a lot of amplifiers and perhaps at least one signal source to VSAC.
Shipping a very large speaker system out of Japan was not going to happen for the VSAC concert.
Unfortunately, the room was very large, the audience was seated very far away, and the large 2-way Altec horn system did not seem to be in very good working order.
We listened to several different amplifiers.
The listening session was in Mono. I think that is what Sakuma does. That was OK, not a problem.
But it seemed like there was lots of distortion. I think it was the speaker, not the amplifiers.
Just seeing Sakuma's amplifiers, hearing his talk, and manner made it worth the trip to Silverdale.
Others may have had different impressions of that listening session.
Sakuma-san brought a lot of amplifiers and perhaps at least one signal source to VSAC.
Shipping a very large speaker system out of Japan was not going to happen for the VSAC concert.
Unfortunately, the room was very large, the audience was seated very far away, and the large 2-way Altec horn system did not seem to be in very good working order.
We listened to several different amplifiers.
The listening session was in Mono. I think that is what Sakuma does. That was OK, not a problem.
But it seemed like there was lots of distortion. I think it was the speaker, not the amplifiers.
Just seeing Sakuma's amplifiers, hearing his talk, and manner made it worth the trip to Silverdale.
Others may have had different impressions of that listening session.