JLM AUDIO

JOETONE wrote: ↑

Sat Jan 28, 2023 12:42 am

Thanks!

Does IC1 need to be fitted at all if using unbalanced out?

Yes, you need IC1 always either a DIP8 or DOA is needed for the GAIN to work.

Which 33R & 47pF are not needed if unbalanced out?

The ones closer to GAIN/POWER

JLM Twenty Five Twenty can run on this PCB +/-24, correct? Yes Just Link C to E? Yes you can but if you want soft start and extra regulation just fit BD681 and turn trim pot up to full to get about 46v (+/-23v) I assume the 2520 note for the DOA 32v +/-16 rails for this PCB is just for Api-Original...

Got it, so I will bypass the rectifier! I can connect directly to the meters, but if I connect directly will that power the lamps? In the original design these meters and bulbs were connected to a shared PCB board that then had a four pin connector that connected to the original radiomixer electron...

......I have a new problem with my 1290. The output transformer seems to be making a clicking noise.....and the leds are flashing on and off in time tiht the output transformer clicks. I think it is probably a power thing as I have tried swapping everything round and the click follows the main gain...

......I have a new problem with my 1290. The output transformer seems to be making a clicking noise.....and the leds are flashing on and off in time tiht the output transformer clicks. I think it is probably a power thing as I have tried swapping everything round and the click follows the main gain...

Hi - Looking similar application with passive EQ makeup gain. A little confused-- RGain - fixed resistor setting the max gain from DOA? GAIN - 10k Rev log applied to control/trim the gain. Do I need to have a resistor value inserted into "RGain" if I just hook up the the C10K pot to "Gain" and that...

Novice Post Incoming :mrgreen: I am retrofitting two PR&E Radiomixer consoles with modern gear (link to old Radiomixer brochure). https://www.steampoweredradio.com/pdf/pr&e/catalogs/Pacific%20Recorders%20and%20Engineering%20Productionmixer%20and%20Radiomixer%20Brochure%201991.pdf I purchased two VU...

Ok - using the calculator Joe provided it appears this power supply would not be a good fit: (21*1.55)+(320*.077)=57.19=meltdown Nathan Yes correct. In the new year I will have a new HV supply that uses a normal off PCB toroid for the first transformer. So a 80VA or large can be used to run the fil...

Hello. I have a BAN related question, and I wonder if anyone here can help. I am thinking of building a fully balanced passive summing mixer (32x4x2) which has 4 group busses feeding one main mix bus. So 32 inputs in total, which are divided into 4 sets of 8 inputs feeding one stereo sub group bus ...

OK, I just built my extender cable. I have 1.23v using the Audio Test program linked. Power on, VU lights up, no LEDs. Not sure if that is correct. VU is pegged to the right. The 0VU trim pot has no effect on the needle. If I switch to GR the zero GR trim pot does work, I'm able to zero that one. T...

I built the LA500A, for the most part it was a breeze, much better lay out and instructions than the last 500 kit I built. I'm hung up on the setup. My extender should be here tomorrow. Is there a video, or some more detailed instructions on the setup? The only one that I'm really stumped on is ste...

c1184701 wrote: ↑

Fri Nov 11, 2022 12:26 am

I'm finding the slow attack mod just a bit too slow on my pair of LA500s. Would it be possible to tweak the attack time by swapping the 100uF capacitor for another value?

-Ross

HI Ross
Yes smaller value caps = faster attack. If you do not know which way +/- is then use Non Polar cap type.

Hi Joe

Got it all done thanks again Joe
These things sound incredible.

Thanks

Sean

Hi Sean
Cool great to hear you got it all working. Yes the PEQ500A is a very sweet EQ and the new C0G caps just make it even better

Hi Joe I have question regarding testing / matching the PEQ500 So im sending a 1khz tone to the 500 rack with eq inserted power off and eq set to in I cant seem to get the trimpot to move the test tone at all. When 500 rack power on i can adjust the level of the 1khz tone Just wondering am i doing ...

Holger wrote: ↑

Sun Nov 06, 2022 5:38 am

The Scorpion works wonderful in my 1 Ru mic pre.

Wow Holger that is a super neat and compact dual tube pre. Amazing.

(I copied the photos locally on to the forum as they weren't showing for some reason)