Search found 1748 matches

by Joe Malone
Fri Jul 23, 2021 9:36 am
Forum: JLM Audio Kits
Topic: Palpigrade Build Thread
Replies: 15
Views: 7731

Re: Palpigrade Build Thread

Hi Joe, Wanted to share the finished Summing Amp with you. This unit is absolutely dead quiet, no noise floor, amazing. The difference in output voltage between the 16 channels is within +/-0,0015V. The sound is really nice and it works beautifully. The only not so nice looking parts are the ribbon...
by Joe Malone
Tue Jul 20, 2021 8:15 am
Forum: JLM Audio Kits
Topic: TREX and TREX2 Transistor regulator kit
Replies: 29
Views: 66137

Re: TREX and TREX2 Transistor regulator kit

fragletrollet wrote:
Tue Jul 20, 2021 4:05 am
Could I just run one of the outputs of the TREX2 into the negative side of the FLIP board to have +/- rails from a single +48 supply? :)
No as TREX & TREX2 can only do +Voltage output rails. The Flip -V side needs a -Voltage in to make a lower regulated -V out.
by Joe Malone
Fri Jul 16, 2021 9:55 am
Forum: JLM Audio Kits
Topic: Palpigrade Build Thread
Replies: 15
Views: 7731

Re: Palpigrade Build Thread

Ooooookay...... Stupid me... I had the ribbon cables that go to my summing board clamped in the wrong direction. So all signals went to ground and all ground wires were in the signal path... Fixed ! OK cool great to hear you worked out the problem. With ribbon cables If using the grey cable with re...
by Joe Malone
Wed Jul 07, 2021 9:46 am
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 13
Views: 1141

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

I forgot to mention that the blue LED is also noticeably brighter than the amber one. Best to send me some photos of the built comp to my email to check over for you. But basically sounds like a solder short and or resistor values in the wrong place for led. The metering is correct for the first po...
by Joe Malone
Fri Jul 02, 2021 11:31 am
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 13
Views: 1141

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

I forgot to mention that the blue LED is also noticeably brighter than the amber one. Best to send me some photos of the built comp to my email to check over for you. But basically sounds like a solder short and or resistor values in the wrong place for led. The metering is correct for the first po...
by Joe Malone
Wed Jun 30, 2021 11:32 am
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 13
Views: 1141

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

Joe, Mea culpa- it was indeed a test-setup failure on my end. Installed it in the rack and it works flawlessly. People, don’t be like me! Order your extender! Thanks Cool great to hear you got it working :-) Please if you have any comments and/or photos of your JLM Audio gear in your rack please pu...
by Joe Malone
Tue Jun 29, 2021 4:01 pm
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 13
Views: 1141

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

Well, I’ve screwed something up then. Not getting the 5v. If I’m reading this right, and I’m probably not, the schematic refers to IC2 for voltage drop, but I can’t see IC2 anywhere? Is the 5v a divider someplace I can trace back? FWW I get 2v across S2. The 5v reg is a To-92 transistor looking 78L...
by Joe Malone
Tue Jun 29, 2021 10:40 am
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 13
Views: 1141

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

Ok, thanks. They looked to be parallel so I wasn’t too concerned. Guess I missed the memo on the extender… Made a small edit above- fired it on my bench with 16v supply and am able to zero meter but not getting anything in GR mode. I am feeding it balanced input from an HP200. “Get an extender” is ...
by Joe Malone
Tue Jun 29, 2021 9:52 am
Forum: JLM Audio Kits
Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Replies: 13
Views: 1141

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

Hello, I’ve just (fingers crossed) finished building this. Excellent packaging, directions et al! One point - the BIO500T pcb has 8 holes around the optos, not matching the 4 shown on pix. One question. I don’t have a good way to reach these trim pots with it racked up. Can I fire it on the bench w...
by Joe Malone
Sun Jun 27, 2021 4:45 pm
Forum: JLM Audio Kits
Topic: 8 Channel Relay Switch Build Thread
Replies: 29
Views: 23626

Re: 8 Channel Relay Switch Build Thread

Hi Joe I do the assembly like the picture on the previous post but I haven't signal output on 'open' when I 'turn' on the switches... On 'normally closed' signal is passing but when I turn 'on/off' the switch nothing happen + I'm not hearing the common relay click noise. When I check the voltage i ...
by Joe Malone
Thu Jun 17, 2021 11:58 am
Forum: JLM Audio Kits
Topic: BA BA2 BA4 BAD Dual99v Build Thread
Replies: 350
Views: 469252

Re: BA BA2 BA4 BAD Dual99v Build Thread

Is it OK to have another op amp soldered under the DOA if the IC1/A (pins 1,2 and 3) are lifted and connected appropriately when using the BA (basic) PCB? That way you could for an example drive a balanced transformer like LL1539 (though without mixed feedback). Obviously with the output caps as th...
by Joe Malone
Sun Jun 06, 2021 8:02 pm
Forum: JLM Audio Kits
Topic: AUX8 Build thread
Replies: 6
Views: 2223

Re: AUX8 Build thread

AUX8 & SUM8 Schematics now on each thread
by Joe Malone
Sun Jun 06, 2021 12:03 am
Forum: JLM Audio Kits
Topic: SUM8 Build Thread
Replies: 5
Views: 1820

Re: SUM8 Build Thread

Hy i have recived pcb. Can i get more info about this sum: Which ic is used Is er mouser or anders part number for 16pin plug and cable Is there list for parts in this project? Thanks in advance Added SUM8 schematic & BOM to first post You can use any dual opamp like NE5532A, NE4562, LME49720, OPA2...
by Joe Malone
Sat Jun 05, 2021 9:13 pm
Forum: JLM Audio Kits
Topic: 8 Channel Relay Switch Build Thread
Replies: 29
Views: 23626

Re: 8 Channel Relay Switch Build Thread

Hi Does the Schematic link is the right way to connect it, switching them by pair/stereo ! I will use 12v Relay and +12v power supply and as I understand regulator will be not need or does it still need and/or better/recommend with !? thanks & care F Yes schematic you have drawn is correct. You can...
by Joe Malone
Thu May 27, 2021 9:04 am
Forum: JLM Audio Kits
Topic: VU2 stereo VU buffer kit Build thread
Replies: 108
Views: 123519

Re: VU2 stereo VU buffer kit Build thread

Please disregard my posts. User error. I hadn’t adjusted the pots far enough. I put a multimeter set to Mv and quickly saw that I just needed to keep turning the pots to get the readings I was looking for. Thanks again! Cool great to hear you got it working. Yes the 25 turn trim pots need lots of t...