No insulator needed for the output mosfets in case that is what you are referencing. Just thermal paste
Ive been listening almost all day. Even with lower bias it sounds wonderful. While it's not a clean build it still is relatively quiet. I have a little hum on the channel with the longer signal cable. All should be resolved when building mono's. 😎
no wonder that you have some hum, when Donut is ditto under the pcb
to prevent any stray magnetic field, existing shielding should go to proper steel with 30mm thickness
to prevent any stray magnetic field, existing shielding should go to proper steel with 30mm thickness
!!Haha ok, even if it's the super fancy stuff from toroidy?
I guess I won't bother with the fancy looks for the other channel. ZM, do you know of any other suitable donut suppliers in Europe?
I guess I won't bother with the fancy looks for the other channel. ZM, do you know of any other suitable donut suppliers in Europe?
sorry, no
my local vendor is making exquisite products, but (I asked) they aren't willing to ship out of Serbia
anyhow - it's only logical tyo order the same one for second channel
or order a pair somewhere else, keeping this one as solo for some other purpose
my local vendor is making exquisite products, but (I asked) they aren't willing to ship out of Serbia
anyhow - it's only logical tyo order the same one for second channel
or order a pair somewhere else, keeping this one as solo for some other purpose
You happen to have anything new in the pipeline that requires +-34 volts?😁
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BigBadaBoom ? (Isn't that From the Fifth element?)
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BigBadaBoom ? (Isn't that From the Fifth element?)
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I will need an orange (two?) chassis for the Bigbadaboom amp(s)...
Will you put together the Bigbadabing preamp to go with it?
Will you put together the Bigbadabing preamp to go with it?
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Oh Boy,
Bring on all the classics🤣
Well, Iron Pre will be my Multipass!
Re big Bada Bing, Steven van Zandt has agreeable music to listen to!
Bring on all the classics🤣
Well, Iron Pre will be my Multipass!
Re big Bada Bing, Steven van Zandt has agreeable music to listen to!
Do you use a single slb for both channels?
How is it doing when you drive both channels with 100w @ 400-500hz?
How is it doing when you drive both channels with 100w @ 400-500hz?
I already made 2 Multipass preamps more than worthy to trickle BigBadaBoom(s) - one is Iron Pumpkin (as much I can produce) and Iron Pre - unlimited production for PitchFork wearing masses
What I need to make in future is damngood child of Pumpkin, able to drive bridged F4 and then some
Life is good and Night is still young
What I need to make in future is damngood child of Pumpkin, able to drive bridged F4 and then some
Life is good and Night is still young
@Zen Mod
".. child of Pumpkin, able to drive bridged F4 and then some.."
Oh, no, there goes Tokyo, go go,Godzilla Alek...
"What glows in the dark
And drives bridged F4s?
Go, Go, Godzilla...
.. Oh no,
There go the bridged F4s!
Go Go Godzilla..."
YES!
You know, I can't retire until I get a preamp driving twin, bridged F4s.
".. child of Pumpkin, able to drive bridged F4 and then some.."
Oh, no, there goes Tokyo, go go,
"What glows in the dark
And drives bridged F4s?
Go, Go, Godzilla...
.. Oh no,
There go the bridged F4s!
Go Go Godzilla..."
YES!
You know, I can't retire until I get a preamp driving twin, bridged F4s.
Not the first album with Godzilla, but my favorite cover. Awesome in glorious 12 inch vinyl.
ZM - need ideas.
XA252 SIT. 32v rails / 1A7
I was going through power up and set up sequence. One channel behaved perfectly.
Other channel was perfect until I installed the jumper. I released some magic smoke, so I immediately killed power. No fuses blown. It looks like R46 is blown. Perhaps other items, too. I powered up again briefly and I see rail voltage for offset.
I decided to put down the tools and rest for the night before I begin taking the board off the heatsink and looking more.
Ideas?
XA252 SIT. 32v rails / 1A7
I was going through power up and set up sequence. One channel behaved perfectly.
Other channel was perfect until I installed the jumper. I released some magic smoke, so I immediately killed power. No fuses blown. It looks like R46 is blown. Perhaps other items, too. I powered up again briefly and I see rail voltage for offset.
I decided to put down the tools and rest for the night before I begin taking the board off the heatsink and looking more.
Ideas?
Attachments
Yes, JP1 is what I installed and saw the problem.
I have XLR Pins 1/3 shorted, and RCA +/- shorted. There is a possibility that my XLR jumper was "iffy". I may also add clip leads for next time. I'll have a look at the parts you mention and try again.
I have XLR Pins 1/3 shorted, and RCA +/- shorted. There is a possibility that my XLR jumper was "iffy". I may also add clip leads for next time. I'll have a look at the parts you mention and try again.
Problem solved. I replaced the blown up R46 and Q9. The IRF510 tested OK, so I reinstalled it.
I tested and wrote down voltages for good and bad channels. They looked similar.
So then I tested resistances around the jumper and inputs. Aha, the bad channel looked funny. I had a small solder bridge on the bottom of the board in those resistors around JP1 and inputs. Easy fix once diagnosed. Amp is now set up at 32V / 1A7 with <2mV offset with jumpers installed.
It sings on the crappy bench speakers. Later tonight I will fire it up on Tannoys. And I'll get a little XA252 SET vs SIT listening opportunity this weekend.
to ZM!!!!
I tested and wrote down voltages for good and bad channels. They looked similar.
So then I tested resistances around the jumper and inputs. Aha, the bad channel looked funny. I had a small solder bridge on the bottom of the board in those resistors around JP1 and inputs. Easy fix once diagnosed. Amp is now set up at 32V / 1A7 with <2mV offset with jumpers installed.
It sings on the crappy bench speakers. Later tonight I will fire it up on Tannoys. And I'll get a little XA252 SET vs SIT listening opportunity this weekend.
to ZM!!!!
