Where can I find a simple 45 SE schematic? Eventually I will build all three, 2A3, and 300B I have been wanting to do this for a long time and I am ready! I am looking to keep it very simple, so if you can recommend me a schematic that would be great!
Thanks
Thanks
I did this as a small project for my son last year, then offered it up as a DIY project on AC. Also have a 2A3 version, but would use something different for a 300B. I can send anyone interested the PDFs and RTFs for cleaner schematics and BOM lists. They sound very nice using good parts and a clean layout, specs are excellent (within 1dB past 30KHz with good OPTs) if you get some good (read NOS) tubes and match them up well.
Regards, KM
PS - larger direct jpeg image here... hope it's viewable.
http://image66.webshots.com/566/4/45/43/2900445430062123407ZaJGuO_fs.jpg
An externally hosted image should be here but it was not working when we last tested it.
Regards, KM
PS - larger direct jpeg image here... hope it's viewable.
http://image66.webshots.com/566/4/45/43/2900445430062123407ZaJGuO_fs.jpg
The Bugle might be a good choice if built with good iron...
http://www.hificollective.co.uk/a/article4.html
http://www.hificollective.co.uk/a/article4.html
Yes, the Bugle article has some design choices explained and some good formulas for calculation of certain circuit parameters and values. You can get the entire article in PDF and a good recommended read here:
www.wavelengthaudio.com/bugle.pdf
Personally I just don't care for SRPP stages, but at least Gordon chose a great tube, the 12AY7. I would still recommend the split balance from my design. With a good 45 you can get hum levels balanced out much lower than using a combined balance.
Regards, KM
www.wavelengthaudio.com/bugle.pdf
Personally I just don't care for SRPP stages, but at least Gordon chose a great tube, the 12AY7. I would still recommend the split balance from my design. With a good 45 you can get hum levels balanced out much lower than using a combined balance.
Regards, KM
kmaier said:
Yeah that would be great!
dreamtoneamps-at-gmail-dot-com
RockysDad said:
Thats an interesting design too, would have to look into SRPP ... not up to speed with the hi-fi circuits.
So basically we have one using a 12AY7 and the other a 12AT7, why these vs. say a 12AX7 or a 12AU7? What other preamp tubes are normally used on a 45 design?
What Iron would you guys recommend?
Thanks for the data!
Hello Kmaier
'I can send anyone interested the PDFs and RTFs'
Yes please my email address is jyiannak@hotmail.com
Yours Sincerely
John
'I can send anyone interested the PDFs and RTFs'
Yes please my email address is jyiannak@hotmail.com
Yours Sincerely
John
RMS said:
12AX7s don't really have the drive capability due to the low currents these typically run. The 12AU7 may not have enough gain (u= 20) and this is more of an RF type than a good audio type.
RMS,
Tried to send you PDFs and RTFs to your requested email account, the mail server prevented it, possibly due to attachments. They are certainly clean and free of any bad code. Maybe something specific with the gmail servers. if you have another mail account you'd like me to try let me know.
Anyway, there are all kinds of input/driver tubes used for SE amplifiers... to each his own actually. I've used all of the ones you've listed plus several others. It gets down to the actual application and circuit requirements, which are basic design choices. The 12AX7 has a lot of gain but not a lot of current capability, the 12AU7 is inverse, i.e., low gain and much higher current capability while the others are in between. I selected the 12AT7 as it fit the circuit topology best. It yielded enough gain and had the ability to sink enough current for the cathode follower. Neither of the others fit this application as well.
Regards, KM
Tried to send you PDFs and RTFs to your requested email account, the mail server prevented it, possibly due to attachments. They are certainly clean and free of any bad code. Maybe something specific with the gmail servers. if you have another mail account you'd like me to try let me know.
Anyway, there are all kinds of input/driver tubes used for SE amplifiers... to each his own actually. I've used all of the ones you've listed plus several others. It gets down to the actual application and circuit requirements, which are basic design choices. The 12AX7 has a lot of gain but not a lot of current capability, the 12AU7 is inverse, i.e., low gain and much higher current capability while the others are in between. I selected the 12AT7 as it fit the circuit topology best. It yielded enough gain and had the ability to sink enough current for the cathode follower. Neither of the others fit this application as well.
Regards, KM
RMS, John,
PDFs sent... for some odd reason neither hotmail or gmail servers will accept the RTF docs... probably a default on their configuration. Will try and convert to something else and re-send.
Regards, KM
PDFs sent... for some odd reason neither hotmail or gmail servers will accept the RTF docs... probably a default on their configuration. Will try and convert to something else and re-send.
Regards, KM
kmaier said:
I would be interested too, so send one to nippe87-at-gmail-dot-com
Id really appreaciate! Thanks!
Got a schematic for the 2A3? I'm starting to gather parts for my next build. Thanks...
rockiesdad1(at)yahoo(dot)com
rockiesdad1(at)yahoo(dot)com
Mark, Bryant,
PDFs sent... enjoy.
Astouffer, yes another good one... ala the Bugle with the 2A3. Sadly, last I spoke with Mike he was not making power transformers. His OPTs are really nice, just wish there were suitable power and choke units to match.
Regards, KM
PDFs sent... enjoy.
Astouffer, yes another good one... ala the Bugle with the 2A3. Sadly, last I spoke with Mike he was not making power transformers. His OPTs are really nice, just wish there were suitable power and choke units to match.
Regards, KM
BRYANT said:
Bryant, mail was returned... error was user greenock1998 does not have an account at yahoo dot com.
Regards, KM
Sorry, It is greenock1998 - at - yahoo - dot - co.th
Would you have Schematic for 50 tube ?
Thank you so much.
Would you have Schematic for 50 tube ?
Thank you so much.
BRYANT said:
Okay, resent.... hopefully you get them. Have not done a design for the 50 DHT. I've looked at these in the past. Not easy to find, usually quite expensive and they require higher operating voltages which make them more expensive per watt when built.
Regards, KM
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