Search found 2059 matches

by Joe Malone
Thu Mar 14, 2024 9:40 am
Forum: JLM Audio Kits
Topic: GEQ500 kit BUILD THREAD
Replies: 6
Views: 21669

Re: GEQ500 kit BUILD THREAD

chairbot wrote:
Thu Mar 14, 2024 4:32 am
Batch number is 230509.

I finally got them metered and they appear to be 15k, thanks for your quick response though.

Its really hard to tell the color by the photo, sorry. (and in person too ha!)
Cool. Yes using a meter to double-check all resistor values is the best way to go when building.
by Joe Malone
Wed Mar 13, 2024 6:59 pm
Forum: JLM Audio Kits
Topic: GEQ500 kit BUILD THREAD
Replies: 6
Views: 21669

Re: GEQ500 kit BUILD THREAD

Here ya go! I did not put them in the board yet, however everything else is soldered in. ok strange that looks like a 10k as the colour code the way you are holding it is backwards. But due to the light hard to tell if second band is black or dark green. If dark green it will be 15k. Wider gap colo...
by Joe Malone
Wed Mar 13, 2024 5:32 pm
Forum: JLM Audio Kits
Topic: GEQ500 kit BUILD THREAD
Replies: 6
Views: 21669

Re: GEQ500 kit BUILD THREAD

Hey there I received this kit today and have been hard at work populating and soldering it together. No issue with the edge board, but I'm now on the Control Board and it appears I may have been supplied with the wrong set of resistors. I have (4) 120ohm resistors rather than the build map's (4) 15...
by Joe Malone
Tue Mar 12, 2024 11:04 am
Forum: JLM Audio Kits
Topic: BA500v2 Mic Pre Amp BUILD THREAD 500/51X
Replies: 39
Views: 52170

Re: BA500v2 Mic Pre Amp BUILD THREAD 500/51X

Hi Joe, Thanks for the reply, then for what kind of opamps/transformer combinations then do I need the 390pf ? Greetings Jasper Kit 2520 opamps are usually very unstable especially if used with VTX / OEP highi ratio transformers and any opamp you see oscillation on the output of the opamp at any ga...
by Joe Malone
Tue Mar 12, 2024 10:54 am
Forum: JLM Audio Kits
Topic: BA BA2 BA4 BAD Dual99v Build Thread
Replies: 376
Views: 828040

Re: BA BA2 BA4 BAD Dual99v Build Thread

caoimhin wrote:
Tue Mar 12, 2024 8:45 am
Building a pair of BAD with JLM14 and JLM2503, and I want to add a 'ratio switch' for the output transformer for 1:1, 1:2, 1:3.

Can I do an idiot check that it's o.k. to just use a 3 position rotary switch like this?:
RatioSwitch.jpg
Yes that is correct :-)
by Joe Malone
Mon Mar 11, 2024 9:41 am
Forum: JLM Audio Kits
Topic: BA500v2 Mic Pre Amp BUILD THREAD 500/51X
Replies: 39
Views: 52170

Re: BA500v2 Mic Pre Amp BUILD THREAD 500/51X

Hi, I have a question, I am using JLM14 as input transformer, JLM99V or JLM Twenty 5 Twenty SMD as Opamp, would do some tests and decide to go with the better sounding opamp. My output transformer is the JLM2503. Now the question is in the PCB GB500v2, for Cload, should I use 390pF or not ?. Please...
by Joe Malone
Thu Mar 07, 2024 7:04 pm
Forum: JLM Audio Kits
Topic: SIDEKICK Rack BUILD THREAD
Replies: 0
Views: 93

SIDEKICK Rack BUILD THREAD

UNDER CONSTRUCTION NOTES & ERRATA None Link to SIDEKICK PCB Front Build map https://jlmaudio.com/builds/maps/SideKickFrontMap.html Link to SIDEKICK PCB Rear Build map https://jlmaudio.com/builds/maps/SidekickBackMap.html Build order 1.Fit 8 x blue 15-edge connector to the front side of pcb. Check n...
by Joe Malone
Wed Mar 06, 2024 11:37 am
Forum: JLM Audio Kits
Topic: NV500 Mic pre BUILD THREAD
Replies: 0
Views: 93

NV500 Mic pre BUILD THREAD

UNDER CONSTRUCTION NOTES & ERRATA R30 is marked on pcb as 100k but is 10k for current orange HPF led to be correct brightness. The 2 x BA283AV SMD plug-in modules have been pre-biased so are plug-and-play and swapable. You can check if bias is correct by measuring the voltage across the 12R 1W resi...
by Joe Malone
Mon Mar 04, 2024 11:36 am
Forum: JLM Audio Kits
Topic: KRAFTWERK Power Supply BUILD THREAD
Replies: 33
Views: 102295

Re: KRAFTWERK Power Supply BUILD THREAD

Thanks, Joe, that's super. Can I just double check one more thing: from my 51X racks, I should wire the rack 'chassis' ground directly to the star point in the PSU case, is that correct, rather than the PCB audio 0v starpoint? Just wire your mains ground to the power supply chassis and onto the 51X...
by Joe Malone
Sun Mar 03, 2024 12:35 pm
Forum: JLM Audio Kits
Topic: KRAFTWERK Power Supply BUILD THREAD
Replies: 33
Views: 102295

Re: KRAFTWERK Power Supply BUILD THREAD

hi Joe - a quick question about Kraftwerk grounding, I'm just trying to make sure I understand why there are two 0V points on those Phoenix output connectors. Audio ground is connected to chassis ground via 10ohm resistor in series with 0.1uF cap, right?, and I thought that's the only way that audi...
by Joe Malone
Tue Feb 27, 2024 2:34 pm
Forum: JLM Audio Kits
Topic: MAC Rack kit Build Thread from October 2023 with slow attack led
Replies: 39
Views: 22032

Re: MAC Rack kit Build Thread from October 2023 with slow attack led

Ok 98.8k in parallel with 831k = 88.3k. So you can try a 1Meg pot. Since pots are +/20% it will not guarantee the pots will be at the same point in the turn of the pot due to the log curve mismatch but can help. Once you balance the ac volts at these 2 points you will need to redo the makeup balanc...
by Joe Malone
Mon Feb 26, 2024 6:39 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 104
Views: 168442

Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X

paulnajar wrote:
Mon Feb 26, 2024 3:03 pm
Total success!

Thank you Joe.

Amazing support. Loving the sound of this thing so far:-) Will most likely build another one before too long

Kind regards

Paul Najar
Cool Paul. Great to hear you got it working and are liking the sound :-)
by Joe Malone
Mon Feb 26, 2024 6:36 pm
Forum: JLM Audio Kits
Topic: MAC Rack kit Build Thread from October 2023 with slow attack led
Replies: 39
Views: 22032

Re: MAC Rack kit Build Thread from October 2023 with slow attack led

Ok here are the measurements CH A had .316 vac and 98.8k ohms with pcb cables unplugged. Ch B had .307 vac and 88.3k ohms with pcb cables unplugged. Settings are, y cable with 1.23vac at inputs. 1.3 ratio, VU, and flat. Ok 98.8k in parallel with 831k = 88.3k. So you can try a 1Meg pot. Since pots a...
by Joe Malone
Mon Feb 26, 2024 12:10 pm
Forum: JLM Audio Kits
Topic: Scorpion Tube power Supply Build Thread
Replies: 34
Views: 29335

Re: Scorpion Tube power Supply Build Thread

There is no filament connected with those previous voltage measurements. The filament is set to 6V right now. These are the original tubes to the preamp. The 48V seems fine. Haven’t put a load on it though The schematic for the mic pre you put up showed 12v filament as the 2 tubes are wired in seri...
by Joe Malone
Mon Feb 26, 2024 11:59 am
Forum: JLM Audio Kits
Topic: MAC Rack kit Build Thread from October 2023 with slow attack led
Replies: 39
Views: 22032

Re: MAC Rack kit Build Thread from October 2023 with slow attack led

Cool. With Y cable and thresholds CCW measure the voltage across the outside threshold pot tags again. If one is higher voltage a resistor can be added to bring it down to match the lower voltage side and then the makeup trim will need to be redone. This can sometimes balance the threshold pot mid ...