(MAIL-IN MODIFICATION SERVICE): FOCUSRITE ISA ONE PREAMP

 ISA One modification Service

To Place your order, simply use the normal checkout process above. Once your purchase is complete you will be contacted with mailing instructions, Work Order#, and Work Order form for our mail in service.

Stock these are already a favorite with a nice Lundahl transformer front end but sound a bit harsh and Midrange pushed.

There are numerous bottle necks in the design that contribute to this designs overly focused and sometimes unflattering sound.

We have taken this design to a new level with the modifications with a full audio path upgrade pulling all of the poor performing audio amps in favor of high performance types as well as a whole slew of other tricks.

About the Modifications:

On these preamps we do a Nice input stage modification using Burr Brown high performance opamps, some de-coupling and coupling techniques as well as some other trade secrets to really put the performance into the preamp section.

Interstage coupling modifications are performed as well as output stage modifications for optimum performance as well.

Finally we address the output stage for the maximum headroom and performance possible from the circuit. 

Finally the power supply is also modified for the lowest possible noise and higher current delivery to accommodate the new modifications.

The result is a very warm large sounding preamp that is focused with a lot more headroom, bandwidth and musicality. 
The noise floor is also lowered and the audio image is clear and extremely musical.

Overall I would say these compete with almost any preamp at around twice the cost with the modifications and meet our Price-to-Performance criteria.