Just got my Krell Kav250a power amp and trying to match it up to my Yamaha Theatre amp outputs and I don't have enough gain! Krell needs 2.15 V rms for full output and the Yamaha will only output 1.4 V rms before it trips/shuts down. I need a further 6 db - any suggestions ? Can one modify the front end of the Krell?
Peter
Peter
Hi,
you could add +4dB gain line drivers to the outputs of the theatre source.
A gain of 4dB gets your signal upto maximum.
You could alter the feedback in the Krell for an extra 4dB of gain, but I cannot recommend this solution.
I very much favour good line drivers to minimise the effect of cables and parasitics on your wanted signal.
Look up the BF862 threads. I think one of them discusses a +5dB line driver stage. Very similar to a +0dB B1 in implementation.
There are a number of headphone amplifiers that make excellent line drivers, Diamante (needs lots of matched BJTs) and Peranders ssb01
you could add +4dB gain line drivers to the outputs of the theatre source.
A gain of 4dB gets your signal upto maximum.
You could alter the feedback in the Krell for an extra 4dB of gain, but I cannot recommend this solution.
I very much favour good line drivers to minimise the effect of cables and parasitics on your wanted signal.
Look up the BF862 threads. I think one of them discusses a +5dB line driver stage. Very similar to a +0dB B1 in implementation.
There are a number of headphone amplifiers that make excellent line drivers, Diamante (needs lots of matched BJTs) and Peranders ssb01
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Probably the best solution will be to replace the Yamaha with something that doesn't "trip/shut down". Any reasonable preamp, diy or commercial will do this.
I think the Yamaha shuts down is because at this level its own power amps are clipping ( even though they are not being used - they are hard wired "in") even if no speakers are being driven. Will have to look I think for a good sound processor / preamp and then get another power amp for the centre/surround. You would think commercial stuff would at least agree to voltage levels between interfaces!!
Peter
Peter
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