Search found 1775 matches

by Joe Malone
Sat Oct 16, 2021 9:25 am
Forum: JLM Audio Kits
Topic: LA500A stopped working
Replies: 5
Views: 132

Re: LA500A stopped working

P+ and P- measure 11.1 Ohm S+ and S- measure 22.4 Ohm Thanks for helping out! Ok output transformer is ok. Listening to the output at high level can you hear any thin low level audio? If you turn threshold fully CCW and turn up the makeup does the bad audio level go up at all? If yes does the threa...
by Joe Malone
Tue Oct 12, 2021 12:15 pm
Forum: JLM Audio Kits
Topic: LA500A stopped working
Replies: 5
Views: 132

Re: LA500A stopped working

HI Photos don't show anything unusual.

With the LA500A removed from rack on bench let me know the ohms you get between P- & P+ ? and S- and S+ ? pads behind the transformer plug on the main pcb. Do not unplug and ribbon cables.
by Joe Malone
Sun Oct 10, 2021 4:42 pm
Forum: JLM Audio Kits
Topic: LA500A stopped working
Replies: 5
Views: 132

Re: LA500A stopped working

Please attach some photos of the LA500A inside do I can check it over for you.
by Joe Malone
Tue Oct 05, 2021 10:30 am
Forum: JLM Audio Kits
Topic: MONO Ver2 Mic pre kit BUILD THREAD
Replies: 18
Views: 54806

Re: MONO Ver2 Mic pre kit BUILD THREAD

Gday Joe, Just a question about Rload for the JLM14 (normal version). The build instructions specify a 2k2 but my kit doesn't include one of these, is the 2k7 in the parts list supposed to be for the same purpose? Cheers! Jarrah HI Yes in Mono kit we have found 2k7 works better fitted as Rload and ...
by Joe Malone
Mon Sep 27, 2021 10:16 am
Forum: JLM Audio Kits
Topic: VU BUFFER & PEAK LED KIT BUILD THREAD
Replies: 126
Views: 155662

Re: VU BUFFER & PEAK LED KIT BUILD THREAD

Ok Rewired as above Adjusted meters and they do work...... but After turning the amp off and on again they only way I can get them going again is to quickly wake them up by turning the volume up to almost 100% for a brief moment ? Progress I guess. Richard Have you checked the 12v voltages. What do...
by Joe Malone
Fri Sep 24, 2021 3:44 pm
Forum: JLM Audio Kits
Topic: VU BUFFER & PEAK LED KIT BUILD THREAD
Replies: 126
Views: 155662

Re: VU BUFFER & PEAK LED KIT BUILD THREAD

The saga continues :) Fired up the amplifier this morning and there is no response from either VU meter. I must be wiring something incorrectly. I have attached my wiring diagram. Its as though the meters need to be "charged" or "awakened" some how. Any suggestions on the wiring appreciated. Amp.pn...
by Joe Malone
Wed Sep 22, 2021 10:10 am
Forum: JLM Audio Kits
Topic: VU BUFFER & PEAK LED KIT BUILD THREAD
Replies: 126
Views: 155662

Re: VU BUFFER & PEAK LED KIT BUILD THREAD

I think the issue is I am sharing the power supply from the amplifier to power the buffer but don’t fully understand the wiring needed. I use a dc-dc buck converter to reduce the +35v amplifier rail to 12v which powers the buffer. I connect the amplifier input audio rca V+ to the V+ Of the buffer b...
by Joe Malone
Sun Sep 12, 2021 11:46 am
Forum: JLM Audio Kits
Topic: SUM8 Build Thread
Replies: 6
Views: 2749

Re: SUM8 Build Thread

A great example of the type of mixer that can be made with AUX8 & SUM8 at the link below

https://www.jlmaudio.com/forum/viewtopic.php?f=2&t=342
by Joe Malone
Sun Sep 12, 2021 11:45 am
Forum: JLM Audio Kits
Topic: AUX8 Build thread
Replies: 7
Views: 3297

Re: AUX8 Build thread

A great example of the type of mixer that can be made with AUX8 & SUM8 at the link below

https://www.jlmaudio.com/forum/viewtopic.php?f=2&t=342
by Joe Malone
Sun Sep 12, 2021 11:42 am
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 205
Views: 243958

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Taperocket wrote:
Sat Sep 11, 2021 4:45 am
Yes, I regularly keep the threshold pot pulled out for slower attack.
If you remove the leds and have the pots pulled what voltage do you see across the led pads?
by Joe Malone
Sun Sep 12, 2021 11:35 am
Forum: JLM Audio Kits
Topic: 8x8 Line Level Mixer
Replies: 2
Views: 324

Re: 8x8 Line Level Mixer

Holger wrote:
Sun Sep 12, 2021 3:23 am
Here is a preview of my little 1 RU 8x8 Line Level Mixer utilizing Joe's little PCBs.
Holger, Great looking front panel layout especially in 1 unit high rack :-)

Do you have any photos of the inside?

I moved your photos to our server as they were not showing for some reason.
by Joe Malone
Fri Sep 10, 2021 6:04 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 205
Views: 243958

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Taperocket wrote:
Fri Sep 10, 2021 12:31 pm
No, checked for continuity between them and they did not short together.
You are pulling the makeup and threshold pots outwards so they switch on the leds?
by Joe Malone
Fri Sep 10, 2021 12:10 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 205
Views: 243958

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Here are the pics of the main PCB that you requested, Joe. My phone camera seems to struggle with focus on the back of the boards - I hope this works. I ordered a 500 series extension cable to assist with further testing because I can't access the board with my test probes as is. All other function...
by Joe Malone
Thu Sep 09, 2021 12:37 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 205
Views: 243958

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Yes. I will have to reopen tomorrow to take some additional pics, sorry about the focus issue on the last few. The main thing to check if it is back together is that you have +/-15v to 16v on the 2 x 10R at the end of the LA500SC pcb. Can you calibrate the comp ok? Like does the meter light in VU o...
by Joe Malone
Thu Sep 09, 2021 12:01 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp leveling amp BUILD THREAD 500/51X
Replies: 205
Views: 243958

Re: LA500A opto comp leveling amp BUILD THREAD 500/51X

Hi Joe, Not seeing any voltage across the LEDs. I took it apart today to look for shorts, measured the resistors which were fine, checked the header orientations and everything looked good so I’m at a loss. Pics attached. Thanks, BB3A1504-0337-4799-8D93-453BB1454A5B.jpeg2DFA11A2-CA26-415D-BFBD-861C...