blackface deluxe reverb w/ paraphase inverter?

[mort]

Anyone have any idea how using a paraphase inverter instead of a LTP would effect the overall sound of the amp?

In my very crude, non-scientific estimation I'm thinking it would give just a touch of distorted over/under tones to the clean sounds, and possibly soften the attack just a bit but still sound very very nice. I'm loosely basing this on my experience with the 5e9-a tweed tremolux circuit, other tweeds that don't have the paraphase, and what I know the blackface deluxe reverb sounds like.

Thoughts?

[Jazz P Bass]

I believe that the LTP, being a differential amp, will behave better when it starts to distort.

[KevinOConnor]

Hi Guys

The paraphase should have a warmer tone all the way around. This is because the signal to one output side passes through an extra gain stage and will behave that extra veil of tube character that the first side does not. This will skew the harmonic balance of the drive signals to be warmer.

The Schmitt tends to cancel even harmonic distortions leaving odds, which can be harsh if too many or add to a sense of cleanliness if few. Note that fender went to theSchmitt exactly for this reason, and to have sufficient drive for ever-larger output stages.

Have fun

[J M Fahey]

If you are interested in paraphase go straight to the source, very well explained and covering all variants:
The Valve Wizard -Paraphase

[Mike Sulzer]

Hi Guys



Note that fender went to the Schmitt exactly for this reason, and to have sufficient drive for ever-larger output stages.

Have fun

I think the LTP (Schmitt) should have less voltage drive capability than the paraphrase because you lose some voltage across the tail.

[Mike Sulzer]

If you are interested in paraphase go straight to the source, very well explained and covering all variants:
The Valve Wizard -Paraphase

But I think stating that the version with the common cathode resistor has a bit of positive feedback is missing the point. The positive feedback from the second tube cancels the negative feedback in the first tube resulting from an un-bypassed cathode resistor. Thus the circuit saves a resistor and a bypass capacitor. In the so called floating version it might save two bypass capacitors since you might want one in the second stage in order to keep its open loop gain high in order to increase the accuracy of feedback stabilized gain.