Impedance and other things

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Paul
Posts: 30
Joined: Sat Mar 24, 2007 5:16 pm

Impedance and other things

Post by Paul »

Hi all,

Couple of questions. I have 4 channels of BAs with different Op Amp/Input Transformer configs and Im thinking i'd like to mod them so they're got the same op amps/input transformers.

1. Currently none of the channels have variable impendance. What would this give me and how does it modify the sound of the pres? Is it something those who have implemented feel is a must?

2. Any recommendations for the op amp/input transformer combo that people love the most? Currently I have

BA1 jlm14 + opa264ap
BA2 OEPA26A3C + opa264ap
BA3 jlm14 + JLM99v
BA4 OEPA26A3C + JLM99v

They'd be used for drums, guitar, bass + vocals. I havent really had a good chance to do more that guitars (Acoustic) and vocals with these BAs at the moment. Or be damned and leave them all diff configs?

thanks all

paul.

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Joe Malone
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Re: Impedance and other things

Post by Joe Malone »

Paul wrote:Hi all,

Couple of questions. I have 4 channels of BAs with different Op Amp/Input Transformer configs and Im thinking i'd like to mod them so they're got the same op amps/input transformers.

1. Currently none of the channels have variable impendance. What would this give me and how does it modify the sound of the pres? Is it something those who have implemented feel is a must?

2. Any recommendations for the op amp/input transformer combo that people love the most? Currently I have

BA1 jlm14 + opa264ap
BA2 OEPA26A3C + opa264ap
BA3 jlm14 + JLM99v
BA4 OEPA26A3C + JLM99v

They'd be used for drums, guitar, bass + vocals. I havent really had a good chance to do more that guitars (Acoustic) and vocals with these BAs at the moment. Or be damned and leave them all diff configs?

thanks all

paul.
OEP + JLM99v is the best for vocals and acoustic instruments while
JLM14 + JLM99v is the best on drums and bass.

Most people build 2 pairs of the above in a BA4. So 2 x JLM99v would bring yours up to this.

Variable impedance is extremely useful giving the mic pre a large range of tonal change which often saves the need for any EQ .
Joe :-)
JLM Audio
Capturing Audio without Injury

Paul
Posts: 30
Joined: Sat Mar 24, 2007 5:16 pm

Re: Impedance and other things

Post by Paul »

thanks for the info Joe. Sounds like impedance and transformer/op amp combos are what i'll go with in the very near future.

thanks.

paul.

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