After I've built a single ended 6L6 d'light (https://ampgarage.com/forum/viewtopic.php?f=4&t=30871) which was much to my liking, I now am planning the build of a d'lite preamp into a ltpi and then an ecc99 outputstage in push pull for a whopping 2-5 watts.
Does anyone here have any experience with anything like that?
ECC99 push pull with dumble preamp --> became a stombox preamp
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ECC99 push pull with dumble preamp --> became a stombox preamp
Last edited by TBN on Sun Aug 29, 2021 4:07 pm, edited 1 time in total.
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Dr Tony Balls
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Re: ECC99 push pull with dumble preamp?
Sort of! Awhile ago I set off on a quest to build a true bedroom amp that mimic'd the big boys. By that I mainly mean i wanted it to be push pull and I wanted it to be with pentode output tubes. I had seen a schematic and article about a push-pull EF86 over at Ampbooks.com, but it seems that article isnt there anymore. The schematic is here though:TBN wrote: ↑Wed Aug 11, 2021 12:08 pm After I've built a single ended 6L6 d'light (https://ampgarage.com/forum/viewtopic.php?f=4&t=30871) which was much to my liking, I now am planning the build of a d'lite preamp into a ltpi and then an ecc99 outputstage in push pull for a whopping 2-5 watts.
Does anyone here have any experience with anything like that?
https://www.ampbooks.com/mobile/amp-tec ... h-test.gif
Anyway, I started with something like that. Preamp > LTPI feeding that output section. I didnt like it for some reason or another that I cant remember, but that led me to try using ECL84s as the power tubes and those stuck. The ECL84 (6DX8) is a triode and pentode in the same envelope. Since I had already had the preamp and LTPI done I didnt need to use the triodes in the ECL84s, but I believe I heard they are of a similar nature to those in a 12AT7. Anyway a NOS ECL84 is like $6 so who cares. I started with a Fender-ish preamp and changed it up for something more Dumble-ish. It wound up sounding great, though at ~2 watts its still a bit loud for my neighbors (NYC...apartments) so I added a little attenuator on the output. Here's what I wound up with:
I build effects and amps and do custom builds to order. Boom.
Site: http://ballseffects.com/
Site: http://ballseffects.com/
Re: ECC99 push pull with dumble preamp?
In my experience, these small amps do a pretty good job with a clean, but the OD doesn't sound convincing 
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Re: ECC99 push pull with dumble preamp?
That is adorable
I would agree about the girth just not being there with small amps in small cabinets. There was a build here called Matt's 86 Special which I remember sounding quite good though. It was a single EL84 running at 250V on the plate and the OD channel used an EF86.
Re: ECC99 push pull with dumble preamp?
i did that and IMO is not good approach..because triodes on output are missing high end sparkle of pentodes output and sound is too dull..TBN wrote: ↑Wed Aug 11, 2021 12:08 pm After I've built a single ended 6L6 d'light (https://ampgarage.com/forum/viewtopic.php?f=4&t=30871) which was much to my liking, I now am planning the build of a d'lite preamp into a ltpi and then an ecc99 outputstage in push pull for a whopping 2-5 watts.
Does anyone here have any experience with anything like that?
for small power PP i can recommend my favorite small power tube EL/PL95! in pentode mode you can squeeze 6W from theoretical 7W after 1w loss in OPT, or 4W depending of the anode voltage 250-260VDC / 200-220VDC.
Last edited by bepone on Fri Aug 27, 2021 3:03 pm, edited 1 time in total.
Re: ECC99 push pull with dumble preamp?
that one black on the left, several watts "dumble-ish" preamp with 2x 12B4A on the output
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Re: ECC99 push pull with dumble preamp?
Thanks for the feedback; I love those tiny dumble-style amps!
For my own project I was very much in doubt about the output stage, so I decided to take the easy solution and leave out the outputstage alltogether: result is a stompbox d'lite-ish preamp.
I used a 12Vdc to 220Vdc voltage pump to obtain my B+, which is rather low-ish. but I decided to build it nonetheless to hear how it sounds.
It sounds great; has the drive character resembling my earlier built SE 6L6 D'lite amp. It was a bit too bright, so I left out the 270pf bright cap over the 220K grid stopper resistor of v1b. The local nfb on v1b was also left out.
Pics:
For my own project I was very much in doubt about the output stage, so I decided to take the easy solution and leave out the outputstage alltogether: result is a stompbox d'lite-ish preamp.
I used a 12Vdc to 220Vdc voltage pump to obtain my B+, which is rather low-ish. but I decided to build it nonetheless to hear how it sounds.
It sounds great; has the drive character resembling my earlier built SE 6L6 D'lite amp. It was a bit too bright, so I left out the 270pf bright cap over the 220K grid stopper resistor of v1b. The local nfb on v1b was also left out.
Pics:
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Re: ECC99 push pull with dumble preamp --> became a stombox preamp
very good, i like it! soldano GTO style chassis! 
i did the same 10 years ago ,"Dumble ish preamp", like OD pedal for other amps..developed my own chassis in local metalshop, my friend on cnc and lathe jumped in and produced nice mahagony knobs with maple inserts.. with small russian tubes 6n17b inside!
i did the same 10 years ago ,"Dumble ish preamp", like OD pedal for other amps..developed my own chassis in local metalshop, my friend on cnc and lathe jumped in and produced nice mahagony knobs with maple inserts.. with small russian tubes 6n17b inside!
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Re: ECC99 push pull with dumble preamp --> became a stombox preamp
My electronics supplier has these housings, with tubesockets and predrilled, originally destined for their own tube stompbox kit. It fitted my requirements perfectly: I only had to drill 3 additional holes for od controls and bright switch.
Dymo labeling, because its easy and I like the industrial look of these labels on a blank aluminium chassis.
Yours looks fabulous; very well finished!
Re: ECC99 push pull with dumble preamp?
These Dumble preamps are awesome! You guys are my heroes... 
Funny, I'm currently planning something along these lines. Thanks for the pointer!
Re: ECC99 push pull with dumble preamp --> became a stombox preamp
A few years ago, a friend of mine made several preamps in a similar style. I'll just show you the photos, for inspiration. They are amazing!
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Last edited by alkuz1961 on Sun Aug 29, 2021 7:12 pm, edited 1 time in total.
Re: ECC99 push pull with dumble preamp --> became a stombox preamp
By the way, there was one in the style of a Dumble but I didn't have any photos left in the finished form. Only the creation process itself...
I hope he will not be offended with me for posting these photos without asking 
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Re: ECC99 push pull with dumble preamp --> became a stombox preamp
I gave the first one to a friend of mine as a birthday present and built number two for myself.
I definitely improved on lay-out and lead dress.
Further I added the following changes:
Used 0,5W metal film resistors in stead of 1w carbon film
Used ceramic disc caps in stead of silver mica
Separated grounding for signal, wire screens, and general ground for cathodes and 12V
Added mid boost switch (wrongly labeled "deep")
Added the LNFB on v1b (the white "blob" on the picture contains the cap and 4 10M resistors)
It's very silent (no noise or hum, less so than the first one) and sounds much to my liking.
I definitely improved on lay-out and lead dress.
Further I added the following changes:
Used 0,5W metal film resistors in stead of 1w carbon film
Used ceramic disc caps in stead of silver mica
Separated grounding for signal, wire screens, and general ground for cathodes and 12V
Added mid boost switch (wrongly labeled "deep")
Added the LNFB on v1b (the white "blob" on the picture contains the cap and 4 10M resistors)
It's very silent (no noise or hum, less so than the first one) and sounds much to my liking.
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Re: ECC99 push pull with dumble preamp --> became a stombox preamp
I did find the balance between clean (pushed to slightly compressed/crunchy) and overdirive hard to dial in.
After changing the 180k series resistor with the od level pot for an 68k one it's much better!
After changing the 180k series resistor with the od level pot for an 68k one it's much better!