Colossal wrote: ↑Tue Dec 31, 2019 1:08 pm
Very nice, Tony! A lot of history in those cool, old parts.
For sure. Plenty of great sounding amps were built using some of these old parts, Hopefully and maybe some of that mojo will rub off in this build or it could turn out to be nothing special? Then again that's the fun part about building your own the suspense in how it will turn out. This has always been for me the great motivator in doing these Dumble style amps since we know there is so much potential lying in the ODS design.The question is? can you pull it off.. This amp was really thrown together from parts I had left over and what fell behind my bench Who knows maybe this recipe of old parts turns out to be something spectacular!! or just another Friggin amp
We'll See
Thanks for following along!
I can no longer blame the parts
Tony
" The psychics on my bench is the same as Dumble'"
Colossal wrote: ↑Tue Dec 31, 2019 1:08 pm
Very nice, Tony! A lot of history in those cool, old parts.
For sure. Plenty of great sounding amps were built using some of these old parts, Hopefully and maybe some of that mojo will rub off in this build or it could turn out to be nothing special? Then again that's the fun part about building your own the suspense in how it will turn out. This has always been for me the great motivator in doing these Dumble style amps since we know there is so much potential lying in the ODS design.The question is? can you pull it off.. This amp was really thrown together from parts I had left over and what fell behind my bench Who knows maybe this recipe of old parts turns out to be something spectacular!! or just another Friggin amp
We'll See
Thanks for following along!
I can no longer blame the parts
Tony
A parts bin special.... they're sometimes the best amps , it's looking great already so my money is on a great sounding amp too.
stelligan wrote: ↑Wed Jan 01, 2020 12:15 pm
Can't wait to hear how it turns out.
Happy smoke free New Year!
Me too! Btw. I know it will sound good since I used your OPT!
A parts bin special.... they're sometimes the best amps , it's looking great already so my money is on a great sounding amp too.
The PB-ODS it is! I like it. BTW. After I fire it up and working I will do some quick clips before any mods or changes so let's see if it has any warts If I do need to make some final tweaks I will, of course, share them with everyone.
Happy New Year guy's
Tony
" The psychics on my bench is the same as Dumble'"
Abe5150 wrote: ↑Thu Jan 02, 2020 12:26 am
What kind of transformers did you use?? I saw your video of the low plate Music Man, sounds great.
Thanks ABE!
Transformers are all "used" Power is 1980's Schumacher Twin Showman ( Export taps) OPT is Schumacher from Yamaha/ Soldano T-100 100W 6L6 (4-8-16 ohm) and a Twin/Showman Choke
Amp will be Heavy!!
Tony
" The psychics on my bench is the same as Dumble'"
Filaments and Relay transformer wired. Still waiting on mini toggle switches and a few other parts. I did change a few resistors I found and want to try like the CC on the OD entrance. Should have it fired up in the next day or so. Will let you know when it has a pulse
20200120_200507.jpg
Tony
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Last edited by talbany on Thu Feb 06, 2020 2:53 am, edited 1 time in total.
" The psychics on my bench is the same as Dumble'"
I sure appreciate your knowledge and experience with these amps and the generousity you bring in sharing the experiences and what you know about them! I always look forward to reading your posts. The philosophical mindset that you bring in how you approach these and think about them is useful also.
Might I be captain obvious here? This surely doesn't look like a #124! V1b grid stopper 270k//470p? OD grid stoppers are different too if I judge the colours correctly. 56k and 200k? also those bypass caps. feedback around v1b looks different too. Interesting!
rootz wrote: ↑Tue Jan 21, 2020 6:23 pm
Might I be captain obvious here? This surely doesn't look like a #124! V1b grid stopper 270k//470p? OD grid stoppers are different too if I judge the colours correctly. 56k and 200k? also those bypass caps. feedback around v1b looks different too. Interesting!
22uf cathode bypass caps too almost fender stock rather than the 4.7uf or 10uF HAD preferred.
rootz wrote: ↑Tue Jan 21, 2020 6:23 pm
Might I be captain obvious here? This surely doesn't look like a #124! V1b grid stopper 270k//470p? OD grid stoppers are different too if I judge the colours correctly. 56k and 200k? also those bypass caps. feedback around v1b looks different too. Interesting!
22uf cathode bypass caps too almost fender stock rather than the 4.7uf or 10uF HAD preferred.
You going for more low end Tony?
M
We'll see This one no doubt is an experiment? Dumble used 4.7uF's all the way up to 50uF in some ODS's. My Music Man has the 22's in V1 and is pretty well balanced. I don't mind the extra low end as long as it stays tight! The extra filtering I have on the screen's and the Tantalum bypass caps and V1B LNFB should help with this. I do have some 10uF's ready to go if it's too bass heavy. Again we'll see what happends.
BTW. here is what I am thinking!..124 has a larger OD entrance trimmer value that along with a 250K OD level which also adds more low end but he used 4.7''s. Mine is 100K trimmer and 100K OD level so it might be a touch more low end in OD than 124 but not by much. The only thing that concerns me is 124 was a Skyliner and mine is a Classic, So this has me a little curious as to how it balances out. If I like the clean which I think I will then I may have to go down to 4.7's on V2. No way I would do this on a 50w but I might just get away with it being a 100???
The OD should snarl much like 183
Tony
Last edited by talbany on Wed Jan 22, 2020 1:44 am, edited 4 times in total.
" The psychics on my bench is the same as Dumble'"
rootz wrote: ↑Tue Jan 21, 2020 6:23 pm
Might I be captain obvious here? This surely doesn't look like a #124! V1b grid stopper 270k//470p? OD grid stoppers are different too if I judge the colours correctly. 56k and 200k? also those bypass caps. feedback around v1b looks different too. Interesting!
Hey Captain good eyes.
The 200k measured out to be 192K (close enough) I also normally use a 180K OD Level feeder resistor and only had a 150K Iskra so the series resistance on V2B kind of balances out )X the Miller Capacitance.) . If anything the OD will be a touch darker and smoother which is OK with me
V2A says 75K but measures out at 72K again close enough. I also wanted to use these Pihers on the grid feeders as they seem to give me a certain sound I like so I sacrifice being off a few K for the sound of the resistor.. I have a 252k on the V1B just something I want to try since I like what it does to the mids. I may go back though so that one is suspect.
124 Was a Skyliner and this is a Classic so my intent was to not chase after a particular ODS number but stray a bit off the reservation and try something different for a change. It may work out it may not. We'll see a part of the fun of rolling my own
BTW.V1B FB is stock 2X10 Meg on each side w/.047 6PS
Tony
" The psychics on my bench is the same as Dumble'"
Who knows maybe this recipe of old parts turns out to be something spectacular!! or just another Friggin amp 
, it's looking great already so my money is on a great sounding amp too.
