pazzo63 wrote:Ciao yes classic tone i guess it s a better option than hammond, the voltages and the power transformer choice is a crucial factor for the best Dumble sound in my experience BEST REGARDS
I wish there were a way to A/B test if I'll like the higher voltages, seeing as how a transformer change is a big deal.
I do happen to have a Mesa Tremoverb sitting right next to my HRM. It easily switches between 440 and 420 on the EL34 Plates with the flip of a switch (5% change, similar as between 448 and 465). I prefer the lower voltage on that one.
pazzo63 wrote:Ciao yes classic tone i guess it s a better option than hammond, the voltages and the power transformer choice is a crucial factor for the best Dumble sound in my experience BEST REGARDS
I wish there were a way to A/B test if I'll like the higher voltages, seeing as how a transformer change is a big deal.
I do happen to have a Mesa Tremoverb sitting right next to my HRM. It easily switches between 440 and 420 on the EL34 Plates with the flip of a switch (5% change, similar as between 448 and 465). I prefer the lower voltage on that one.
Ciao that s a matter of taste tremoverb it s a different circuit so i guess it s not comparable from dumble circuit , at least give it a try , 465 volts are fantastic for dinamycs, you get both worlds fender and marshall , at least for me (sorry for my english) Greetings from Italy
I was thinking about that. I'd need to set it at 129V based on my calculations and I suspect the heaters, 12V circuit and LED would tolerate that.
I still think it would be odd if it sounded better at the higher voltage. I can't think of any other amp where cranking it up on a variac improved it.
I kind of missed out on the flurry of 183 activity, but it looks like a 183 build would have this same issue (of needing a higher power "Twin" power transformer). I suspect someone has already done that experiment.
It would make a good reason to get a variac, seeing as I don't have one.
I was thinking about that. I'd need to set it at 129V based on my calculations and I suspect the heaters, 12V circuit and LED would tolerate that.
I still think it would be odd if it sounded better at the higher voltage. I can't think of any other amp where cranking it up on a variac improved it.
I kind of missed out on the flurry of 183 activity, but it looks like a 183 build would have this same issue (of needing a higher power "Twin" power transformer). I suspect someone has already done that experiment.
It would make a good reason to get a variac, seeing as I don't have one.
I liked the sound of my #102 clone a bit better when I upped the voltage on the variac. That's actually one of the reasons I got the higher voltage MC power transformer. After messing around with the new PT I found that I like the preamp plate voltages in the standard 200VDC range, but with the power tube plates around 465-470. The clean sounds better with the preamp voltages higher but the OD gets a bit too tight. The higher power tube plates seem to help keep the amp focused and punchy overall. Anyway... For my amp, I like preamp soft and smooth and the poweramp tight, clean and punchy.
I kind of missed out on the flurry of 183 activity, but it looks like a 183 build would have this same issue (of needing a higher power "Twin" power transformer). I suspect someone has already done that experiment.
There was a few of us that used a custom Heyboer Twin PT that was 340VAC, it gets you close if not on the documented 460V.
I kind of missed out on the flurry of 183 activity, but it looks like a 183 build would have this same issue (of needing a higher power "Twin" power transformer). I suspect someone has already done that experiment.
There was a few of us that used a custom Heyboer Twin PT that was 340VAC, it gets you close if not on the documented 460V.
I kind of missed out on the flurry of 183 activity, but it looks like a 183 build would have this same issue (of needing a higher power "Twin" power transformer). I suspect someone has already done that experiment.
There was a few of us that used a custom Heyboer Twin PT that was 340VAC, it gets you close if not on the documented 460V.
We used one similar, only it had an extra 6.3V winding for the relay. Personally, I would trying different preamp and output tubes before I would be chasing 10 volts on the plates with a new PT. There's absolutely nothing wrong with 448V on the plates either. Forget the comparisons here to other non-HRM circuits. I would be rolling preamp tubes, I don't like your preamp voltages for an HRM, too high, especially V2.
TM
Last edited by ToneMerc on Fri Nov 30, 2012 1:23 am, edited 1 time in total.
Hi i think the voltages of Dumble 183 are fantastic also for a hrm circuit, try to get closer to those voltages and you will be happy!! to me that is the Dumble sound irrespective the circuit you are using CHEERS
ToneMerc wrote:We used one similar, only it had an extra 6.3V winding for the relay. Personally, I would trying different preamp and output tubes before I would be chasing 10 volts on the plates with a new PT. There's absolutely nothing wrong with 448V on the plates either. Forget the comparisons here to other non-HRM circuits. I would be rolling preamp tubes, I don't like your preamp voltages for an HRM, too high, especially V2.
TM
Thanks all for the input , I really appreciate it.
V2 too high?
I was looking at the "Dumb Bell" notes PDF and thinking my voltages are too low:
V2pins 1=229 3=2.03 6=227.5 8=2.03
from the document titled: The following is a transcript of an anonymous conversation dealing with the construction of a Dumb Bell amp.
Thanks for the link, that one looks like it would swap right in. It looks like it is missing the orange lead that goes to ground that the original TF-130 has. I wonder if that makes any difference.
ic-racer wrote:Thanks for the link, that one looks like it would swap right in. It looks like it is missing the orange lead that goes to ground that the original TF-130 has. I wonder if that makes any difference.
I believe that the orange wire on the TF130 and the original Fenders are just some sort of electrostatic shield. I don't think that's going to make much of a difference, honestly.
