Search found 1573 matches

by Joe Malone
Thu Dec 05, 2019 1:18 pm
Forum: JLM Audio Kits
Topic: POWER PLANT BUILD THREAD
Replies: 29
Views: 18759

Re: POWER PLANT BUILD THREAD

Hi Joe, I CHanged the Regs and everything works fine now. Thank you for your help. I have a question too. In the power plant page, its written that can feed 4 modules. Even those telefunken or neumann cards with 2 channels per module?? Thank you! Cool great to hear you got it working ok. As long as...
by Joe Malone
Tue Dec 03, 2019 9:03 pm
Forum: JLM Audio Kits
Topic: ADM 1540 EQ MOD INPUT to BALANCED IN
Replies: 6
Views: 7598

Re: ADM 1540 EQ MOD INPUT to BALANCED IN

I think i worked it out by myself. There's a huge pad on the input, 40db. It's extremely hard to read from the schematics. What i ended up doing is this. A new pad in front of the input transformer (Lundahl LL2603 1:1) thats attenuating 25dB.The secondary of the 2603 is terminated via 2k plus 1,6nf...
by Joe Malone
Sat Nov 30, 2019 7:40 am
Forum: JLM Audio Products
Topic: VUPPM 500 Meter Calibration ?
Replies: 3
Views: 34

Re: VUPPM 500 Meter Calibration ?

Hello Joe, Oh ! Then I have decalibrate my new VUPPM :oops: I'm not in my studio this week so I can't recalibrate it now but when I try the first time, my problem was that the VU/PPM trimpots had no action. (The green VU level didn't move) Is it possible ? I will try again ASAP and tell you ! Thank...
by Joe Malone
Wed Nov 27, 2019 10:05 am
Forum: JLM Audio Products
Topic: VUPPM 500 Meter Calibration ?
Replies: 3
Views: 34

Re: VUPPM 500 Meter Calibration ?

Hello Joe, I just received your wonderful VUPPM 500 Meter, thank you very much ! I have tried to calibrate the VUPPM as describe : Send in 1k tone at 0dFS or +18dBu to 500 Input for left and Output for right. Set mode to VUPPM mode RED PPM with GREEN VU over the top. Adjust Left and Right level tri...
by Joe Malone
Wed Nov 13, 2019 10:45 am
Forum: JLM Audio Kits
Topic: POWER PLANT BUILD THREAD
Replies: 29
Views: 18759

Re: POWER PLANT BUILD THREAD

Hi thanks for your reply. I cleaned the pcb with isopropilic, but is dificult to take a picture showing the traces, cause it shines with the light I hope you can see something. So I have to change one of the regs, or better both? one or both The trim for the 24v now doesn't works, I dont know if I ...
by Joe Malone
Tue Nov 12, 2019 9:34 am
Forum: JLM Audio Kits
Topic: POWER PLANT BUILD THREAD
Replies: 29
Views: 18759

Re: POWER PLANT BUILD THREAD

Oh, I thought I sent it attached. Let me try again The bottom of the pcb needs a good clean with isocol or iso prop and toothbrush to see properly but I can see that one centre leg on the trimpot has never been soldered so will not work. Since the 3 x 120R burnt the 48v reg is likely to be dead sho...
by Joe Malone
Wed Nov 06, 2019 10:10 am
Forum: JLM Audio Kits
Topic: POWER PLANT BUILD THREAD
Replies: 29
Views: 18759

Re: POWER PLANT BUILD THREAD

Hi! Im having some problems with my second power plant. Some 120r resistors got burned and I changed them with new ones. Now the 48v rail marks 24v And 24v. Rail marks 35,6 v. Im sending you a photo if hepls. Thank you very much! Ok yes attach some photos of the top and bottom of the pcb here or em...
by Joe Malone
Thu Oct 31, 2019 9:52 pm
Forum: JLM Audio Kits
Topic: AC/DC & POWERSTATION KIT BUILD THREAD
Replies: 319
Views: 273102

Re: AC/DC & POWERSTATION KIT BUILD THREAD

Hi Joe, Here is my sad tale: I built a v3 AC/DC with 48v and +/- 28v and it worked great for many months powering a DIY mic pre. Then one day it blew a mains fuse, I disconnected from the mic pre, replaced the fuse, and 48v had turned into 5v. I then replaced R7 because it was blown up and D10 beca...
by Joe Malone
Thu Oct 31, 2019 3:03 pm
Forum: JLM Audio Kits
Topic: AC/DC & POWERSTATION KIT BUILD THREAD
Replies: 319
Views: 273102

Re: AC/DC & POWERSTATION KIT BUILD THREAD

Hi Joe, Here is my sad tale: I built a v3 AC/DC with 48v and +/- 28v and it worked great for many months powering a DIY mic pre. Then one day it blew a mains fuse, I disconnected from the mic pre, replaced the fuse, and 48v had turned into 5v. I then replaced R7 because it was blown up and D10 beca...
by Joe Malone
Wed Oct 30, 2019 10:36 am
Forum: JLM Audio Kits
Topic: JLM99V as summing amp
Replies: 12
Views: 516

Re: JLM99V as summing amp

Perfect. This inductor should be as close to the -in as physically possible. Yes, that's where I put it. 8) Do you have a copy of this sections schematic? Sure: ACA_Booster.jpg Everything, including the dotted part, is actually there. As in the summing section I have used bipolar caps and will remo...
by Joe Malone
Tue Oct 29, 2019 9:57 am
Forum: JLM Audio Kits
Topic: Tardigrade Build Thread
Replies: 5
Views: 615

Re: Tardigrade Build Thread

Thanks Joe. I thought offset might be the problem. Since adding output caps is not really an option I guess I'll use modern op amps after all... Audio path Cap is 1uF MKT polyester not ceramic. If lower input impedance is need then cap needs to be increased to 10uF etc so Non Polar electro will be ...
by Joe Malone
Tue Oct 29, 2019 9:54 am
Forum: JLM Audio Kits
Topic: JLM99V as summing amp
Replies: 12
Views: 516

Re: JLM99V as summing amp

Thanks Joe. I use a 20uH inductor at the moment. Self-wound with a ferrite bead. I couldn't detect a change of the frequency response in the audio band. Perfect. This inductor should be as close to the -in as physically possible. BTW, what about the buffer stage after the fader? In the feedback pat...
by Joe Malone
Sat Oct 26, 2019 10:35 am
Forum: JLM Audio Kits
Topic: Tardigrade Build Thread
Replies: 5
Views: 615

Re: Tardigrade Build Thread

Hi Joe, looks like this is exactly what I need as balancing/output driving stage for my discrete multichannel DAC! :D I'd like to use NE5532 (got old Signetics ones that I consider the best sounding op amp out there), any reason why they wouldn't work here? What can you expect WRT to SNR and THD? T...
by Joe Malone
Sat Oct 26, 2019 10:24 am
Forum: JLM Audio Kits
Topic: JLM99V as summing amp
Replies: 12
Views: 516

Re: JLM99V as summing amp

Cool, thanks! I forgot to add an inductor to the schematics. I added it between the input cap and the op amp's inverting input to reduce RF reaching the summing amp and increase stability. This shouldn't make a difference WRT to implimentation, I think. Yes inductor is good idea as long as it is sm...
by Joe Malone
Fri Oct 25, 2019 5:33 pm
Forum: JLM Audio Kits
Topic: JLM99V as summing amp
Replies: 12
Views: 516

Re: JLM99V as summing amp

Thanks Joe! I had a JLM99V in one of my BAs but it got destroyed accidentally. I remember it sounded better than all the other op amps I've tried... The console has 32 channels + 8 returns, so 40 get summed to each side of the master bus in total. Ok so a gain of 27 max which is easy. Also C15 will...

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