[ACMP investiupgradifications] All things PREAMP
- Thread starter clintrubber
- Start date
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TomWaterman
Well-known member
Yeah I have that pic too. It's obviouly not a schematic error... so I'd guess these trafos needed controlling more so than the originals.
One place to investigate when they arrive...
One place to investigate when they arrive...
Svart
Well-known member
another interesting thing is that the pic of the *possible* preamp that Gyraf found shows IC opamps while the schematic on this thread shows discretes..
I wonder which one of these designs these preamps will be.
Kinda makes me wish I had ordered some..
I wonder which one of these designs these preamps will be.
Kinda makes me wish I had ordered some..
[quote author="TomWaterman"]
Whats up with the excessive damping capacitance on the mic trafo secondary. Standard 10468 requires 180pF not 1000pF.
Wonder if the chinese trafos have substantial ringing and overshoot?
[/quote]
Probably. When we get them, I can test them against the Carnhill equivalents and also see if they've got the best values chosen there. Also, I wasn't sure if the original transformers would have a 12K strapped across the secondary too.
I'm not going to get in the mode where I decide everything is likely to be rubbish and decide what's going to be changed already. I'll test out what's there and see if anything is really holding it back. Just wait until people start discussing coupling caps...
Whats up with the excessive damping capacitance on the mic trafo secondary. Standard 10468 requires 180pF not 1000pF.
Wonder if the chinese trafos have substantial ringing and overshoot?
[/quote]
Probably. When we get them, I can test them against the Carnhill equivalents and also see if they've got the best values chosen there. Also, I wasn't sure if the original transformers would have a 12K strapped across the secondary too.
I'm not going to get in the mode where I decide everything is likely to be rubbish and decide what's going to be changed already. I'll test out what's there and see if anything is really holding it back. Just wait until people start discussing coupling caps...
Baltimore
Well-known member
well, if these are similar to the chameleon labs stuff, and it looks like they are, they should sound pretty f'in good right out of the box. i've used the CL stuff in a few different rooms and can't complain...and i thought that stuff sounded excellent for the price...
Svart
Well-known member
Look at the cards, there are opamps on each board:
ioaudio
Well-known member
overload/clip led for each stage. transistors in the back.
funny way of marking the caps in the schematics.
funny way of marking the caps in the schematics.
TomWaterman
Well-known member
As said there are enough transistors in the photo to form the discrete amp stages and there are so many clip leds on this device. God knows why but that is what the IC's are.
I agree with Roddy, there's not much point deciding to rip them apart before they get here. Chameleons do sound really good, so I don't think these will sound bad at all.
Roddy mentioned coupling caps... I don't see many tantalums but must listen first before judging.
I'll try and organise a shoot out with some real Neve on a variety of sources when they get here. Maybe piano, drums, ac guitar and vocal.
-T
I agree with Roddy, there's not much point deciding to rip them apart before they get here. Chameleons do sound really good, so I don't think these will sound bad at all.
Roddy mentioned coupling caps... I don't see many tantalums but must listen first before judging.
I'll try and organise a shoot out with some real Neve on a variety of sources when they get here. Maybe piano, drums, ac guitar and vocal.
-T
gareth.h.rees
Member
[quote author="TomWaterman"]
I'll try and organise a shoot out with some real Neve on a variety of sources when they get here. Maybe piano, drums, ac guitar and vocal.
[/quote]
That would be amazing! Except it may make me wish I ordered more!
Cheers
Gareth
I'll try and organise a shoot out with some real Neve on a variety of sources when they get here. Maybe piano, drums, ac guitar and vocal.
[/quote]
That would be amazing! Except it may make me wish I ordered more!
Cheers
Gareth
Jim50hertz
Well-known member
[quote author="TomWaterman"]I'll try and organise a shoot out with some real Neve on a variety of sources when they get here. Maybe piano, drums, ac guitar and vocal.
-T[/quote]
+1 on that. Tom, that's a fine offer and I think would be very useful to the folks who've bought these. Many thanks :thumb:
Cheers
Jim
-T[/quote]
+1 on that. Tom, that's a fine offer and I think would be very useful to the folks who've bought these. Many thanks :thumb:
Cheers
Jim
crazydoc
Well-known member
Looks like 3Q3 got left hanging. Doesn't inspire a lot of confidence in the schematic.
okgb
Well-known member
2nd , not turning this into a bitchfest ............which i 3rd
how may i help
how may i help
clintrubber
Well-known member
Been away for a week, amazed a bit by all the action here (and indeed lame to see all those other discussions 'elsewhere').
Cool the schematics popped up, thanks :thumb:
I guess it'd be safe to say now that the output-stage of the ACMP-81 is identical to the -73 & -84 (so class-A, '3055, gapped TX bla bla bla) or what do you guys think ?
Bye,
Peter
Cool the schematics popped up, thanks :thumb:
I guess it'd be safe to say now that the output-stage of the ACMP-81 is identical to the -73 & -84 (so class-A, '3055, gapped TX bla bla bla) or what do you guys think ?
Bye,
Peter
[quote author="clintrubber"]
I guess it'd be safe to say now that the output-stage of the ACMP-81 is identical to the -73 & -84 (so class-A, '3055, gapped TX bla bla bla) or what do you guys think ?[/quote]
I reckon this is probably likely.
I guess it'd be safe to say now that the output-stage of the ACMP-81 is identical to the -73 & -84 (so class-A, '3055, gapped TX bla bla bla) or what do you guys think ?[/quote]
I reckon this is probably likely.
