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SE tube in mono amp

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Well after much research and studying I am ready to build my first amp. A modest endeavor , Mono amp with a full range speaker.
My difficulty is I am not sure which tube to use for the output.
It will be low power 3 - 5w. Doing a search on the board iy seems that people like the w300b , but is that over kill for this project.


Jeff(tenderfoot)
 
hi, do a google search for 6aq5 a lovely little tube quite plentifull and relatively cheapto get and nice sounding to boot as some would verify, there are numerous jap hobbiests who have posted se circuits on it, combine this little tube with the little hammond [ the designation of which escapes me right now] though I know of some who are offering 2a3 triode kits using this traffo ie: angela..... -se op traffo and you are in business..... must be getting old and demented as I can see i'm all over the place writing this... hope you can make some sense of this rambling.... merry xmas and all the best from sunny down under cheers tomcat:blush:
 
I'm listening to Diana Krall Live in Paris on the speakers in my avatar on a three tube SE amp right now. Each half of a 12AX7 driving a 6BQ5 in SE for stereo. I cannot believe how much tone this re-capped little Magnavox console pull has!

Shweeeeeet!
 
Re: blah

tenderland said:
I guess after further review 6bm8 is a ecl86 . similar to prev mentioned ecl82. well I got it narowed down ... to 100 tubes:bigeyes:

6BM8 is an ECL82... it was designed for the dual use of TV tube & audio tube... it is like half of a 12AT7 and an EL95 in the same bottle. Puts out about 3-3.5 W in pentode, half that in triode.

Here is a tread on a 6BM8 amp Morse built:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=14694

The ECL86 was the audio specific successor to the ECL82. Like half a 12AX7 + an EL84, 4-4.5W in pentode.


Both can be used to make nice little amps.

dave
 
Why not try something with less common valves? I don't know how adventurous you want to be with your first project, so maybe I shouldn't be bringing this up, but thse valves look so cool 😀

VHF double tetrodes like the 829B or 832 are rarely used for anything, and thus are fairly cheap. Pete Millett says that he bought 6 RCAs and 2 Mullards for the price of a Sovtek 2A3. Many more could be had if you had a 300B budget!

An externally hosted image should be here but it was not working when we last tested it.


Details of Pete Millett's 829B amplifier here, and schematic.

Also, there seems to be an 832 SE amplifier under development in this thread.

Edit: The picture shows up rather big here, oh well....

I forgot to say, this set up gives around 5W output per channel triode connected. No triode mode curves are shown on his site, but Paul De Raymond Leclercq (7N7 on this site) prepared some curves and is graciously willing to share them if you email him.
 
schematic

I have a question concerning schem posted by Pete


Scherzo


1) not certain about the feed back connection and how to go from pentode to triode mode.

does the fill connect to green , yellow on the power trany
due to the fact the fills are in series in the tube ?


Jeff
 
audiousername said:
829B or 832 are rarely used for anything, and thus are fairly cheap

Cheap they are... i got all of $3 for an 829 with a Johnson socket... I have some 815s stashed to make an amp someday...

dave
 

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Scherzo

Hi Jeff,

1) not certain about the feed back connection and how to go from pentode to triode mode.

I have the fb and pentode/triode mode switches. I tried them once.. If you need more power than 1W you should build another amp. The fb and pentode mode just doesn't sound so good.

does the fill connect to green , yellow on the power trany
due to the fact the fills are in series in the tube ?

The trannies in the schema are sold with the kit. If you build the amp without purchasing the kit(as I did) you need to find suitable trannies for the amp. I used ECL86 tubes with 6,3V heater and Hammond 125ESE for audio. Please read the end of this page: scherzo



Hope I could help!
-Pete
 
EL 84

I have decided to go with a EL84 , using the Hammongd 125ese for
OPT. Every schematic I have has the tube used as pentode , would it be advantagous to use as triode ? I think the Sq is more important than the gain for this project . Any recomendations on a driver tube
each print I have has an ECC85 or 83 but my amp will be Mono.

I am getting sick of reading Sh#*% I want to build something

Jeff
 
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