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Re: JLM 60Watt Power AMP Kit

Posted: Mon Aug 23, 2010 8:58 pm
by greenmanhumming
OK, thanks, I figured the AMP wouldn't be loading it much.

I've used a separate 48v supply as I want to keep the phantom to spec.

Re: JLM 60Watt Power AMP Kit

Posted: Thu Nov 10, 2011 6:50 pm
by flaheu
HI folks,

I've just bought 4 amp kits for my Rhodes super sattelite rig.
The goal is to replace the internel amp of the 2 speaker boxes.
The original amps are rated at 100W rms each, which I doubt.
So, I think I'm going to make a bidged 120W per speaker.
But I have no idea how to connect them in bridge mode at the speaker output and at the input.
Do I have to connect the input in parallel ?
What about the volume control ? double gang 10K pot ?
The signal going to the jlm bridged module will be unbalanced (coming from the Rhodes on board preamp), how to connect them ?
Recommended TX for bridged config is 2x 18V, but is 160VA tx optimum ?

Thanks in advance.

Cheers

Re: JLM 60Watt Power AMP Kit

Posted: Thu Nov 10, 2011 8:29 pm
by Joe Malone
Image

160VA 2 x 18vac will work perfect for one 120w bridge amp but use 300VA 2 x 18vac for two 120w bridge amps.

Coming Soon 8 channel amp on 184mm x 82mm PCB that I just designed for Dolby Labs.

Image

Re: JLM 60Watt Power AMP Kit

Posted: Thu Nov 10, 2011 10:57 pm
by flaheu
Hi Folks,

Thanks Joe, you rule :) best world class service !!!!

is the pix below ok for my unbalanced bridged volume controled 120W amp 8)

Image


-I suppose that the output must be isolated from the chassis
-for the mute switch a DPDT is necessary ?, contact closed muted, or the other way around ?

possible to get the schematics, i'm not the best to redraw from pcb :oops:

Thanks, I'm going to post photos when everything's done.

Cheers

Re: JLM 60Watt Power AMP Kit

Posted: Thu Nov 10, 2011 11:21 pm
by Joe Malone
Your drawing is correct. Just wire both mute terminals together and switch to a -v for sound. If mute not needed just wire mute terminal permanently to -v.

Re: JLM 60Watt Power AMP Kit

Posted: Fri Feb 03, 2012 1:42 am
by wizardofoz
The new boards arrived today and as luck would have it all was ready to roll within an hour or so as the rest of the build was all done and dusted....

Here is the final result

Image

Nice one Joe...little gems you have there...and now they are mine too :D

Re: JLM 60Watt Power AMP Kit

Posted: Sat Feb 04, 2012 9:12 am
by Joe Malone
They are a great looking set of mono block amps with very neat layout. Excellent build :-)

Only thing is there should be a earth/ground wire from the IEC block ground terminal to chassis to make the chassis 100% safe.
Or does that filter IEC have the metal shield come around to under the 2 mounting bolts go it is already connected to chassis?

Re: JLM 60Watt Power AMP Kit

Posted: Wed Feb 08, 2012 2:26 am
by wizardofoz
The shield is grounded at the screws and wraps the IEC and filter/fuses (2) completely, with the earth tab passing through the shield too. I metered it out and its all good.

Client very happy... Replacing a Bryston 2b lp pro with a horrortone monitor :P Plus a new setup in another studio.

Now I just want that 8 Channel board for my home setups. This could be a great amp for the Linkwitz Orions!

Re: JLM 60Watt Power AMP Kit

Posted: Sat Feb 25, 2012 4:50 am
by wizardofoz
How is that 8 Channel board coming along Joe?

Any more details like ps requirements and the like?

Re: JLM 60Watt Power AMP Kit

Posted: Wed Mar 07, 2012 1:03 am
by slb1959
Hi,..
Few weeks ago i repair a Active Speaker from a friend. The amp is a 3xlm3886. Two for the woofers and one for the tweeter. I like to make one pair or two for me. I gone by some of your pcb´s, but the shipping cost,.. :(
Ok,.. I work in events with sound. I normaly connect pc´s "laptops" to active speakers.
I made a draw based on your pcb. Can you help to correct me to i can made a good amp.
Sorry,.. my English.

Thanks, Luis from Portugal

ps - congratulations for your kits. "and one usb dac to xlr stereo output?"

Re: JLM 60Watt Power AMP Kit

Posted: Wed Mar 07, 2012 6:11 pm
by Joe Malone
slb1959 wrote:Hi,..
Few weeks ago i repair a Active Speaker from a friend. The amp is a 3xlm3886. Two for the woofers and one for the tweeter. I like to make one pair or two for me. I gone by some of your pcb´s, but the shipping cost,.. :(
No sure what you mean about shipping cost as it should only be about $10 or so to ship several PCB's if you read on the web shop how to do the PCB discount code.
Ok,.. I work in events with sound. I normaly connect pc´s "laptops" to active speakers.
I made a draw based on your pcb. Can you help to correct me to i can made a good amp.
Sorry,.. my English.

Thanks, Luis from Portugal

ps - congratulations for your kits. "and one usb dac to xlr stereo output?"
Drawing is to small for me to read. Post a larger copy so I can see it :-)

Re: JLM 60Watt Power AMP Kit

Posted: Wed Mar 07, 2012 10:05 pm
by slb1959
Hi,...
I hope that picture are with better resoluition.
Can i pay with Paypal?

Thanks, Luis

Re: JLM 60Watt Power AMP Kit

Posted: Thu Mar 08, 2012 8:49 pm
by Joe Malone
slb1959 wrote:Hi,...
I hope that picture are with better resolution.
OK looks right. But are you using the same box and woofers and tweeter as described a few pages back on this thread as this will only work for that exact configuration. Volume control can be done with normal dual 1k to 10k log pot. I can draw how to do this and send with the order.
Can i pay with Paypal?
Yes JLM Audio web shop excepts Paypal.

Re: JLM 60Watt Power AMP Kit

Posted: Fri Mar 09, 2012 12:04 am
by slb1959
Hi,..

"Yes JLM Audio web shop excepts Paypal"
Aceppts or excepts?

The Dingo Pup is a good solution for the input module?
To i by the 3 amps pcb and the dINgO pcb,... or other pcb that you say it´s better.

Thanks, Luís

Re: JLM 60Watt Power AMP Kit

Posted: Fri Mar 09, 2012 7:12 am
by Joe Malone
slb1959 wrote:Hi,..

"Yes JLM Audio web shop excepts Paypal"
Aceppts or excepts?

Woops. Accepts Paypal
The Dingo Pup is a good solution for the input module?
Yes a dingo pup would allow for balanced in to unbalanced out for volume control and then unbalanced output of volume control to balanced out to drive amps with gain if needed. So would be a good idea.
To i by the 3 amps pcb and the dINgO pcb,... or other pcb that you say it´s better.
Are you only making a mono setup ? For stereo you will need double the PCB's
Thanks, Luís
8) :D