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Messages - g1

Quote from: Tassieviking on April 11, 2022, 05:26:52 AMI would not be using the reverb tank you have, I think it should be a 8FB or 8EB tank, you have a working tank so measure the DC resistance of that one and work it out from there.
If you use a tank that has an input that is too low you could burn out the Op-Amp.
He said his tank is 600 ohm at both ends, so 'E' input impedance, same as the Peavey.
Quote from: Enzo on April 10, 2022, 02:22:52 AMIf I recall, this had the little open frame reverb guts.  Just the small spring assembly, no pan around it.  It would be the equivalent of an EB type pan though.
The closest thing for those little mini tanks seems to be the accutronics AMC2EF3, which are cheap but no one seems to have stock right now.

It does seem that 600ohm input is right, so I would suggest Tim try the 600/600 tank he has if there is room for it.  Worst case it will be a bit weak at output end.
The signal routes through R46 to the power amp whether the jacks are in use or not.
It won't function as a loop.  You can use them as either a pre-out, or a power amp in, but not both functions at the same time.
Doh!  Big attachment button at bottom of text box.  :-[
But I get some kind of 'security error' message if I try to attach anything.
Quote from: pinkjimiphoton on March 24, 2022, 04:20:55 PMapparently admin has crippled my ability to upload files. sorry man. i'll try and upload them on diystomps or something.

i guess i did something wrong? wtf?

The whole forum looks very different since yesterday I think it was.  Some kind of update or new software I guess.  I would think there is some bugs to work out rather than anything particular to your account.
I don't see any means of attaching anything either.
Quote from: phatt on March 17, 2022, 03:20:14 AM
Assuming the Alembic is just a stock Fender tone stack
Pretty much.  From the Alembic website:

"The F-2B was inspired by the Fender Dual Showman amplifier. In the late '60's, we routinely added preamp output jacks to Dual Showman amplifiers and substituted an external power amplifier for the built-in quad 6L6's, most usually a MacIntosh 75.

The F-2B came about to provide the same preamp functionality in a rack-mounting package, as the Dual Showman was considerably wider than the standard 19 inch rack
Yes, thermal compensation for the bias to avoid thermal runaway of the output transistors.  With a reading of 1.34 forward v, I think it is a double diode type, which are often seen used for this purpose.

8EB2C1B would be the closest commonly available tank I think.

Quote from: eaudio on January 12, 2022, 03:48:41 AM
RE: JD10 Pots:
I know this thread is old, but all this drama and not one person actually answered the original question?
Check the last post right before yours, he mentions the originals were log pots.   :)
Is it the same breaker tripping every time?
Does your meter have a peak hold function or anything like that?  It may be that the meter is just too slow.
If it's not too involved, you could swap the breakers around and see if the problem follows one particular breaker.  It's not common, but they do get weak sometimes.
So you have found out that a continuity 'beep' is not the same as a short.  That is a good thing to know, as it leads to many errors for novice users.  Different brands have different ranges that will cause the beep, some anything below 40 ohms, some as high as 200 ohms!
If you know the spec for your meter, continuity function can be useful.  But usually for things like looking for an automotive wire that is shorting to the chassis or something.
When reporting resistance always use resistance range.

The 7 ohms you measure at the headphone jack will be the speaker in parallel.  And the common way to disconnect the speaker for headphone use is to disconnect the ground side of the speaker via a switch contact in the phones jack. (with attention to what Phil said about current feedback resistor)
If you have an empty TRS plug to put in the phones jack, it might help with the resistance readings and wiring tracing.
Quote from: g1 on December 27, 2021, 02:28:37 PM
Quote from: dmfp123 on December 23, 2021, 11:48:28 PM
Any source for the schematic?
I could be wrong, but it seems we have not even found out the model # yet?
Perhaps that would be a little bit helpful?  ;)
Quote from: phatt on December 27, 2021, 09:08:13 PM
Mentioned on the first post, Also I linked to a few pictures I found on Reverb site in (post 15) ;)
I'm not trying to be difficult, but unless I am blind, there is no model # in either of those posts.
Schematics are found by model number.  If we had the number, perhaps we would already be looking at the schematic, which would make for a much more fertile discussion.
Apologies if there is no model # to be found on the unit, but if so the OP should just say that.
Quote from: dmfp123 on December 23, 2021, 11:48:28 PM
Any source for the schematic?
I could be wrong, but it seems we have not even found out the model # yet?
Perhaps that would be a little bit helpful?  ;)
Quote from: mikebarg on December 10, 2021, 10:08:58 PM
It's a DB604. According to the datasheet that's a 400V, 3A.
Quote from: Enzo on December 10, 2021, 10:34:20 PM
I saw that data sheet, but in general I expect a 604 bridge to be rated at 6A 400v. 

Was that a download, or was it the 'specs' listed on the datasheets360 page?
That 'specs' page looks to be their own list with a typo.  The pdf they offer on that page shows the part to be 6A. (see attached)
With 4 ohm load, 100W requires 5 amps.  I think you need some leeway there.  I would guess 8 to 10A would be much more reliable.
Amplifier Discussion / Re: Peavey Bandit as speaker cab
November 18, 2021, 02:03:26 PM
Another option is using a closed in-line cable mount jack (like a Switchcraft 121) rather than an open jack & enclosure.  It would not need an enclosure and can be strapped to the inside of the cab.