Search found 2067 matches
- Thu Jan 25, 2024 7:47 am
- Forum: JLM Audio Kits
- Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
- Replies: 108
- Views: 184645
Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Ok, the Threshold pot measures 93k and Makeup pot 9.7k. Similar on other comp. Ok either swap the BIO500T pcbs between comps and see if the high level swaps to the other comp or stays with the current faulty comp. Or unplug the bio ribbon cable from the sc pcb on the faulty comp and do the 2 link t...
- Wed Jan 24, 2024 10:04 pm
- Forum: JLM Audio Kits
- Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
- Replies: 108
- Views: 184645
Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Ok that looks built fine. Unplug the ribbon cable going to the pot pcb and measure the threshold and makeup pots outside solder pads while pots fully CCW. Threshold should measure 100k and makeup 10k. Let me know what you measure.
- Tue Jan 23, 2024 4:37 pm
- Forum: JLM Audio Kits
- Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
- Replies: 108
- Views: 184645
Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Yes, both comps output level is the same as input level when switched to off. No, one of the comps output level does not stay the same when switched to VU/GR. It has more output when switched to VU and GR. Ok remove the jlm99v opamp from comp that goes higher output and send me a couple of clear we...
- Tue Jan 23, 2024 10:17 am
- Forum: JLM Audio Kits
- Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
- Replies: 108
- Views: 184645
Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Hello Joe, I recently went to check calibration on my two LA500A comps and discovered an input level issue. They were built from kits over 5 years ago. I connected to an extender and from my DAW, setup a signal generator plugin to send 1k tone at -18db and set the send level at -4db. On one unit I ...
- Tue Jan 23, 2024 10:10 am
- Forum: JLM Audio Kits
- Topic: BA500v2 Mic Pre Amp BUILD THREAD 500/51X
- Replies: 39
- Views: 56678
Re: BA500v2 Mic Pre Amp BUILD THREAD 500/51X
Am I right in guessing that you think the output attenuator is simply not a good idea, Joe? I found this old thread that quotes you as saying you "would never put an output control on a baby animal because it will take away from headroom and adds output damping" (https://gearspace.com/board/geekzon...
- Thu Jan 18, 2024 10:21 am
- Forum: JLM Audio Kits
- Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
- Replies: 108
- Views: 184645
Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
Yep just desoldered meter so it’s all good. Hope this helps. Worth if you have any pot cleaner to give the inside of the pot a tiny spray and remeasure with pot fully CCW to see if it returns to 10k. Otherwise the pot will need to be removed from the pcb and replaced. Okay so terribly slow with thi...
- Wed Jan 17, 2024 8:08 am
- Forum: JLM Audio Kits
- Topic: AC/DC & POWERSTATION KIT BUILD THREAD
- Replies: 350
- Views: 804215
Re: AC/DC & POWERSTATION KIT BUILD THREAD
Thanks for your input. Just ordered two v4 PCBs so I can try to make it work. If it turns out to not work with the transformer inside the case I will put it in an external (Powerbrick like) box. PS: If anyone is interessted I will come back with my findings once I finished the powersupply exchange....
- Tue Jan 16, 2024 7:58 am
- Forum: JLM Audio Kits
- Topic: AC/DC & POWERSTATION KIT BUILD THREAD
- Replies: 350
- Views: 804215
Re: AC/DC & POWERSTATION KIT BUILD THREAD
Thanks for your input. Just ordered two v4 PCBs so I can try to make it work. If it turns out to not work with the transformer inside the case I will put it in an external (Powerbrick like) box. PS: If anyone is interessted I will come back with my findings once I finished the powersupply exchange....
- Sun Jan 14, 2024 11:57 am
- Forum: JLM Audio Kits
- Topic: AC/DC & POWERSTATION KIT BUILD THREAD
- Replies: 350
- Views: 804215
Re: AC/DC & POWERSTATION KIT BUILD THREAD
For the 1605: (+V1/+16V) = 15.32V @ 696mA (-V1/-16V) = -15.23V @ 800mA (+V2/+8V) = 9.79V @ 17.12mA For the 1603: (+V1/+16V) = 15.41V @ 474mA (-V1/-16V) = -15.44V @ 536mA (+V2/+8V) = 9.93V @ 19.59mA My plan now is to replace the SMPS entirely and replace it with a combination...
- Sun Jan 14, 2024 11:49 am
- Forum: JLM Audio Kits
- Topic: GAIN Mic Pre / Makeup Amp Kit
- Replies: 26
- Views: 29013
- Sun Jan 14, 2024 10:01 am
- Forum: JLM Audio Kits
- Topic: MAC Rack kit Build Thread from October 2023 with slow attack led
- Replies: 39
- Views: 25932
Re: MAC Rack kit Build Thread from October 2023 with slow attack led
Hi Joe, I have been working on the new transformer board and love the new layout. Just wanted to make sure the components on the right of this picture will not be used on this pcb version. Since the 2 pin and jumper are not being used on the ground and chassis like the older board had should I sold...
- Sun Dec 31, 2023 11:45 am
- Forum: JLM Audio Kits
- Topic: Scorpion Tube power Supply Build Thread
- Replies: 34
- Views: 32537
Re: Scorpion Tube power Supply Build Thread
I tried a heatsink like the one linked below which claims 7 C/W on the datasheet but it only helped a little bit https://www.mouser.com/ProductDetail/Wakefield-Vette/274-2AB?qs=VVKQmw408U9hpo53u4A84w%3D%3D The linked heatsink states “ Thermal Resistance: 25 C/W” It is so low in mass it will do very...
- Sun Dec 31, 2023 10:50 am
- Forum: JLM Audio Kits
- Topic: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
- Replies: 108
- Views: 184645
Re: LA500A opto comp MAY 2021 BUILD THREAD 500/51X
This might be a dumb question, but why is the ratio switch a DPDT rather than a SPDT? It looks like it could have been done with a single pole. It is to use the same switch for all toggles and make mounting easier as it stops the toggle twisting when done up. I also often dual contact switches and ...
- Sun Dec 31, 2023 10:46 am
- Forum: JLM Audio Kits
- Topic: Scorpion Tube power Supply Build Thread
- Replies: 34
- Views: 32537
Re: Scorpion Tube power Supply Build Thread
Hello, I’ve just built the scorpion supply and am getting it up and running with a vintage EAB VE12 mic preamp. I’m trying to just work on the preamp on the bench before racking it up so I don’t have proper heat sinking and I can’t get the Filament regulator to stay on - it’s getting too hot and th...
- Fri Dec 22, 2023 9:02 am
- Forum: JLM Audio Kits
- Topic: VU2 stereo VU buffer kit Build thread
- Replies: 139
- Views: 322731
Re: VU2 stereo VU buffer kit Build thread
Ok Replaced 12v led power with regular 12v 2A (new) plug-in power pack. Measured voltages from Vcc-. Vcc+ 12v. All others pins are the same at 6.23v dc. Regardless of hooked input or not. Think the chip is Kaput. The TL072 should have 12vdc on pin 8 and 0v on pin 4. All other pins should be roughly...