TS-990 // Twin Servo Mic Preamp for 500 series

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Hi Guys,

just to clarify... I won't be offering kits anytime soon. I have too much work at the moment and I still need to test the latest revision with the trim control.

Thanks
 
Hi guys,

I finally assembled the latest revision with the 10dB output Trim. Huge Jensen on the output. Lots of clean gain  8)

TS990-Trim-Front.jpeg

TS990-Trim-Side.jpeg

TS990-Trim-Back.jpeg

 
I like the improvements to this rev. The test points and slide switches are good ideas.

Just out of curiosity have you messed around with an M1 style build at all? It seems to me that some of your features may have been inspired by the (amazing) JH 990 doc which shows the M1 bias adjustment and servos etc
 
Fuzz Face said:
Just out of curiosity have you messed around with an M1 style build at all? It seems to me that some of your features may have been inspired by the (amazing) JH 990 doc which shows the M1 bias adjustment and servos etc

Bias adjustment was inspired by the 1984 Jensen's Twin Servo schematic:
http://www.waynekirkwood.com/images/jpg/Jensen_Twin_Servo_Microphone_Preamp_1984.JPG

I love the M1... but I'm not a fan of the "High Gain" push button switch. In certain situation (foley recording for example) you need access to the complete range of overall gain. But they do sound stellar  ;)
 
elskardio said:
Bias adjustment was inspired by the 1984 Jensen's Twin Servo schematic:
http://www.waynekirkwood.com/images/jpg/Jensen_Twin_Servo_Microphone_Preamp_1984.JPG

I love the M1... but I'm not a fan of the "High Gain" push button switch. In certain situation (foley recording for example) you need access to the complete range of overall gain. But they do sound stellar  ;)

Thanks for the link and info. And in general thanks for all the generosity you have shown me with info and parts :)
 
Any chance to add a adjustable HPF to this? That would make it an instant want for me. Could you fit the JT16B transformer on there for the input as well?
 
The only indication you now have that you are overloading the amplifier, is that you will get heavy distortion.
Usually on a microphone peramplifier we find an overload ('almost clipping') indicator, or even a kind of output level meter. I prefer this on any preamplifier.
 
The only indication you now have that you are overloading the amplifier, is that you will get heavy distortion.
Usually on a microphone peramplifier we find an overload ('almost clipping') indicator, or even a kind of output level meter. I prefer this on any preamplifier.
The preamp is usually connected directly to a converter. The converter’s input will clip way before the amp overloads!

Also I’m not discussing the product’s design here… simply offering kits to those who requested one in the past and didn’t get a chance to buy one

Thanks
 
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