Search found 184 matches

by chrisp
Wed Jan 06, 2010 8:37 am
Forum: JLM Audio Kits
Topic: dingo as dual output -10dbV/+4dbu converter.is it possible?
Replies: 5
Views: 16614

Re: dingo as dual output -10dbV/+4dbu converter.is it possible?

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...
by chrisp
Mon Jan 04, 2010 8:41 pm
Forum: JLM Audio Kits
Topic: dingo as dual output -10dbV/+4dbu converter.is it possible?
Replies: 5
Views: 16614

Re: dingo as dual output -10dbV/+4dbu converter.is it possible?

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...
by chrisp
Sun Dec 27, 2009 9:54 pm
Forum: JLM Audio Kits
Topic: VU BUFFER KIT BUILD THREAD
Replies: 66
Views: 277302

Re: VU BUFFER KIT BUILD THREAD

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...
by chrisp
Mon Dec 14, 2009 9:47 am
Forum: JLM Audio Kits
Topic: BAD PCB and kits Now Available
Replies: 17
Views: 67751

Re: BAD PCB and kits Now Available

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...
by chrisp
Wed Dec 09, 2009 3:50 pm
Forum: JLM Audio Kits
Topic: Dual balanced (or unbalanced) outs on a BA?
Replies: 3
Views: 13059

Re: Dual balanced (or unbalanced) outs on a BA?

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 ...
by chrisp
Tue Dec 08, 2009 8:34 am
Forum: JLM Audio Kits
Topic: Dual balanced (or unbalanced) outs on a BA?
Replies: 3
Views: 13059

Re: Dual balanced (or unbalanced) outs on a BA?

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 ...
by chrisp
Fri Nov 20, 2009 9:37 pm
Forum: JLM Audio Kits
Topic: Baby Animal clipping
Replies: 5
Views: 16974

Re: Baby Animal clipping

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?
by chrisp
Wed Nov 18, 2009 8:08 am
Forum: JLM Audio Kits
Topic: Baby Animal clipping
Replies: 5
Views: 16974

Re: Baby Animal clipping

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...
by chrisp
Thu Nov 05, 2009 4:27 pm
Forum: JLM Audio Kits
Topic: BA output caps
Replies: 18
Views: 44226

Re: BA output caps

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...
by chrisp
Thu Sep 24, 2009 12:25 pm
Forum: JLM Audio Kits
Topic: 1290 micro vs Dual 99v
Replies: 5
Views: 16570

Re: 1290 micro vs Dual 99v

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...
by chrisp
Wed Sep 23, 2009 3:05 pm
Forum: JLM Audio Kits
Topic: 1290 micro vs Dual 99v
Replies: 5
Views: 16570

Re: 1290 micro vs Dual 99v

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...
by chrisp
Tue Sep 22, 2009 11:35 am
Forum: JLM Audio Kits
Topic: Dual 99V pre kit vs dual 99V500 pre
Replies: 3
Views: 12717

Re: Dual 99V pre kit vs dual 99V500 pre

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...
by chrisp
Sat Sep 12, 2009 8:18 am
Forum: JLM Audio Kits
Topic: JLM Neve clone vs Golden Age
Replies: 3
Views: 14333

Re: JLM Neve clone vs Golden Age

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...
by chrisp
Fri Sep 04, 2009 3:01 pm
Forum: JLM Audio Kits
Topic: AC/DC & POWERSTATION KIT BUILD THREAD
Replies: 350
Views: 808107

Re: AC/DC & POWERSTATION KIT BUILD THREAD

What jumpers (if any) do you have on the doubler / tripler pads
by chrisp
Fri Sep 04, 2009 9:35 am
Forum: JLM Audio Kits
Topic: AC/DC & POWERSTATION KIT BUILD THREAD
Replies: 350
Views: 808107

Re: AC/DC & POWERSTATION KIT BUILD THREAD

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.