MONO Ver2 Mic pre kit BUILD THREAD

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lordofgrug
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Joined: Wed Nov 14, 2012 2:21 pm

Re: MONO Ver2 Mic pre kit BUILD THREAD

Post by lordofgrug »

Hey Joe,

So I'm hoping to add one of your fet DI kits to the Mono.

My question is, my Mono doesn't seem to handle unbalanced outs, is this normal?
If so can it be modded to handle unbalanced outs?

Is there any other reason why i shouldn't go down this route?
I'd need to mod the fet DI to 10meg input resistance if that makes a difference. I'd do that by changing the two 2M2* resistors to 20meg correct?

Cheers mate

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Joe Malone
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Re: MONO Ver2 Mic pre kit BUILD THREAD

Post by Joe Malone »

lordofgrug wrote:Hey Joe,

So I'm hoping to add one of your fet DI kits to the Mono.

My question is, my Mono doesn't seem to handle unbalanced outs, is this normal?
If so can it be modded to handle unbalanced outs?
It will work with unbalanced outputs fine as long as phantom power is turned off and cable has unbalanced in on pin 2 of the XLR and pin 2 & 3 are shorted together. But the input impedance is low so will only work well with synths and active guitars. Passive pickups and guitars would need a a high impedance input like our FetDI
Is there any other reason why i shouldn't go down this route?
I'd need to mod the fet DI to 10meg input resistance if that makes a difference. I'd do that by changing the two 2M2* resistors to 20meg correct?

Cheers mate
yes changing the input 2m2* resistors to 20Meg would give you 10Meg input impedance. For this make a real difference the cable going to the input of the DI should be kept as short as possible otherwise the cable capacitance will make the impedance at high frequencies less than 10Meg.
Joe :-)
JLM Audio
Capturing Audio without Injury

jsaunders9
Posts: 1
Joined: Mon Oct 04, 2021 4:22 pm

Re: MONO Ver2 Mic pre kit BUILD THREAD

Post by jsaunders9 »

Gday Joe,

Just a question about Rload for the JLM14 (normal version). The build instructions specify a 2k2 but my kit doesn't include one of these, is the 2k7 in the parts list supposed to be for the same purpose?

Cheers!
Jarrah

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Joe Malone
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Re: MONO Ver2 Mic pre kit BUILD THREAD

Post by Joe Malone »

jsaunders9 wrote:
Mon Oct 04, 2021 7:20 pm
Gday Joe,

Just a question about Rload for the JLM14 (normal version). The build instructions specify a 2k2 but my kit doesn't include one of these, is the 2k7 in the parts list supposed to be for the same purpose?

Cheers!
Jarrah
HI Yes in Mono kit we have found 2k7 works better fitted as Rload and wired to 50k log pot (link front and back legs of Z pot together to make 50k)

If this is your first build get the mono working with NE5532A opamp first and then convert it to JLM99v.
Joe :-)
JLM Audio
Capturing Audio without Injury

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