JLM AUDIO

FWIW I use Joe's transformer trick in a couple of applications, including a DI box, and this would certainly fit in a pedal box. The wiring is pretty straightforward. You need 2 transformers (one per channel) and wire each channel as follows Transformer Wire Goes To Red RCA Hot Green RCA Shield Yell...

Hi Pietro In short, no. There is a difference between converting balanced to unbalanced from vice-versa, such that you cannot just run the signal path in reverse to get 2 channels from the one dingo. 2 dingos would of course do it, but that's a real sledgehammer to crack a walnut. Also, the DINGO as...

In theory, yes, but in practice its probably not necessary. Depends on how you implement the LED drivers. However, there's a few IC LED drivers out there that already buffer the input and have schematics for rectification and VU timing/scaling (all of which is what this circuit does), you probably w...

Joe (or anyone) The BAD PCB has separate GAIN paths for each opamp (although they are usually wired with a double gang pot so that both apply equal amounts of gain). It also has an INSERT path (I O 0v) which can be used as a volume control (or a unbalanced signal point for connecting an eq or comp e...

I presume that wiring it balanced the way you describe will result in both signals being in phase, correct? Yep. Incidentally, can you run the 1:1:1 "backward" (i.e. take two signals in, one on 2+/- and the other on 3+/-) and use it as a 2-into-1 mixer? If so, it might be interesting to try wiring ...

Ok, first of all, there doesn't have to be a difference in signal level between balanced and unbalanced - this is a common misconception due to the fact that the default +4dbu connection for "pro" gear is usually TRS or XLR balanced outs, while the -10dbv connection for "consumer" gear is typically ...

The gain pot wiper tab is hot wired to the CW lug, which is connected to ground yes? And the CCW lug has the GAIN output from the PCB?

This is making me a bit worried, though. It seems that my BabyAnimal doesn't have all the gain it should. If I use SM57 I mostly use it with gain at 4 or 5 o'clock. I was in exactly the same position when I was judging gain levels on the basis of my DAW's input meters. I really struggled to get wha...

Err, Joe may wish to step in here if I'm wrong, but my understanding from other posts is that the output cap is still needed even if the supply is bipolar +/-24V, because there is still some DC bias in the output due to the nature of the opamp design. (I really could be wrong about this next part) T...

eerrr, no, Zedman, I think the transformer of the 1290 might be required. I haven't looked into the Neve output amp board circuit, but a lot of that vintage are push/pull transistor designs rather than opamps, and so you can't take the 99V amp rules and apply them to just any circuit. Unless Joe tel...

Zedman The JLM output tranny is fairly transparent and won't really change the sound of the device. You would add it for one of two reasons - (a) because you want the extra few db you can get by wiring it in its 1:2 configuration; or (b) for balanced signal isolation from the downstream gear (the BA...

Hi Millsy My understanding, FWIW, is that the dual 99V will sound as close as makes no difference, whether it is in rack or 500 form, assuming JLM1:4 tranny and 99V amps and that the kit has been properly assembled and wired. I've own a few 1:4 99V BA kits and have heard the 500 series, and really t...

The trouble with the Golden Age pre is that you need to send them to Joe anyway to upgrade the cheap transformers and generally tweak the thing (I know a Golden Age owner who had to do exactly this to get rid of the woolly mush that the stock unit calls its low end). By the time you've done that, wh...

What jumpers (if any) do you have on the doubler / tripler pads

Where are you based, Spendor? There's many JLMers would be happy to meet up and take a look at the board with you to see what's going on.