JLM Baby Animal

[mac]

Have u searched the jlm forum?

 

[dribro]

Hello fellow diyers!

does anybody knows if the OEP 262A2C can be fitted as the LL1578 & XL with 1:10 ratio like shown on the JLM site?

The traffo is 1+1:2+2

Regards,
Adriano

 

[matta]

Hello fellow diyers!

does anybody knows if the OEP 262A2C can be fitted as the LL1578 & XL with 1:10 ratio like shown on the JLM site?

The traffo is 1+1:2+2

Regards,
Adriano

No you'd need to have the OEP 262A3C to achieve that kind of ratio/gain, set it to HIGH RATIO and it would achieve a 1:12.9 Ratio.

Cheers

Matt

 

[dribro]

thank you!

 

[mupson]

Hello,
Since I don't have output transformers, can I integrate the JLM power supply inside the chassis of my BA4 ?
Besides, while roaming for infos on the web, I remember seeing pictures of someone doing surgery on a PS, but I can't find the page anymore...
Does anyone know what that was about ?
Thanx.
M

 

[3nity]

ive done that before.
ive had no problems!
Good luck!

 

[3nity]

Hi you can add a picture by attachement when posting. look and you'll find!

 

[3nity]

See the window when you post a message when youre done you hit the POST button.
well if you look to the left and a few lines upper of that button you ll find the ''Attachements and other options''
thanks.

 

[mupson]

Howdy,
Minor customizing : as I don't have output transformers in my BA4, I was able to use the holes on the back of the chassis to add balanced output jacks.
M

http://www.mupson.com/

 

[mhelin]

Hi,
Anyone know where to get (in EU ) the DPDT toggle switch right angled 90 deg with threaded bushing fitting BA PCB?
JLM ones are Salecom T8021L Series.

 

[mhelin]

Threaded ones seem to be rare. From Digikey found these:

http://search.digikey.com/fi/en/products/7201P3CWAV2SE/CKN9728-ND/2055006 (in stock)
http://search.digikey.com/fi/en/products/M2022SS1W40/M2022SS1W40-ND/1046963 (in stock)
http://search.digikey.com/fi/en/products/100DP1T6B11M7REH/100DP1T6B11M7REH-ND/1803097 (inexpensive, not in stock)

Guess JLM Audio is still the best place to leave an order.

 

[ciscan.81]

Hi BA fans...

I'm building a BA in a 312-style with the following specs:

EA2622 Input transformer
Scott Liebers 2520 red-dot opamp
EA2623-1 Output transformer (wired 1:2)
CL = NF
CZ = 220pf
RZ = 5k1
RL = 15k and 100k log pot
47pF caps changed to 220pF
Output trim 1k dual log pot with 1k series resistors wired after output trans

My question is about input transformer ratios. I know this has been discussed at great length on the 312 thread and others, but I haven't been able to find the specific answers I'm after.

...And so my questions are:

What ratio should I run a EA2622 at in a BA to render a sound similar to a 70's era 312? Low 1:3.5 or High 1:7?

From what I can gather most seem to favour 1:7?

Joe has suggested I should wire 1:3.5:

...it 2 primary windings so low ratio will give 600ohm input with normal 15k load which is 1:3.5 ratio

I thought I'd give him a break from my persistent questioning and offer my query up to the knowledgeable folks around here.

What 'should' the ratio be to give me that vintage 312 tone everyone talks about...does it make a big difference?

I'd also like to know: If I change the ratio of the input trans this also has an effect on the input impedance...? Yes?...So will my variable z pot or series resistor attached to it need changing also? (am I right in thinking a useful input impedance range is something like 150ohm-1500ohms?)

Any thoughts on any of this would be really appreciated.  But please bare in mind when answering I am new to DIY, and still trying to wrap my head around some concepts here! ???

Many thanks

 

[benqbasic]

Hi guys.
I realise this is an old thread. But does anyone have the measurements for the front switches on the BA or a fpd file.

Many thanks.

 

[MatC]

Hi guys,
Unsure if this thread is still active, but hey worth a shot.
I have a BA4 that 1 channel in not functioning correctly on.
The symptoms are that the DI section seems to still function aside from the fact that I cannot gain it up.... Any idea where I should be looking?  I'm guessing its likely a transformer or something like that but just don't want to order a tonne of parts for no reason :/

Cheer
Mat

 

[Edred]

I realise it’s been AGES since anyone’s been here but I thought I’d give it a crack.

Building a V2 BA with a Jlm14, LME49720 op amp, no output trans & using jlm’s 48v supply.

I previously built a V1 & that would’ve required a regulator mod for this op amp (a BD681, 10k res & 33v Zener). Can‘t find a location for a Zener on this pcb so I’m guessing it’s no longer required?

Also, on V1 there was a link required between pins 4 & 7 on the ic for certain op amps, but I can’t find any info regarding this op amp. Any help?

And lastly, is 10k alright for a trim pot before output? Unbalanced.

Fingers crossed. Ta.

 

[craigmorris74]

I realise it’s been AGES since anyone’s been here but I thought I’d give it a crack.

Building a V2 BA with a Jlm14, LME49720 op amp, no output trans & using jlm’s 48v supply.

I previously built a V1 & that would’ve required a regulator mod for this op amp (a BD681, 10k res & 33v Zener). Can‘t find a location for a Zener on this pcb so I’m guessing it’s no longer required?

Also, on V1 there was a link required between pins 4 & 7 on the ic for certain op amps, but I can’t find any info regarding this op amp. Any help?

And lastly, is 10k alright for a trim pot before output? Unbalanced.

Fingers crossed. Ta.

Have you tried the JLM support forum? Joe‘s always been good about answering questions for me there.

 

[ChrisMM]

I realise it’s been AGES since anyone’s been here but I thought I’d give it a crack.

Building a V2 BA with a Jlm14, LME49720 op amp, no output trans & using jlm’s 48v supply.

I previously built a V1 & that would’ve required a regulator mod for this op amp (a BD681, 10k res & 33v Zener). Can‘t find a location for a Zener on this pcb so I’m guessing it’s no longer required?

Also, on V1 there was a link required between pins 4 & 7 on the ic for certain op amps, but I can’t find any info regarding this op amp. Any help?

And lastly, is 10k alright for a trim pot before output? Unbalanced.

Fingers crossed. Ta.

I built a BA for a client with almost this exact configuration. Let's see if I can remember...

The zener isn't needed anymore with the V2 PCB. Instead there is a spot for a trimpot and you trim down the supply voltage to 32V or whatever the LME49720 needs.

I'm pretty sure the link between pins 4 and 7 is not needed for chip op amps. Only for discrete op amps. You can leave it out. I left it out on my build and it worked...

As for the output trim pot, that I cannot answer.

 

[ion]

I would like to know if i can use a marinair 1452 input former (backwards) and a Muses 8920 dip-8 opamp with this kit?
also i plan to power it via xvive p1 for nice mobility (tape field rec)

this pre is powered by phantom power (xlr) right?

is the pcb available in EU or so eone got a spare?