Red Knob Concert Lead info

[rocker1970]

yes...need info on difference between red knob Concert Lead heads...do they actually sound different from non red knobs? why do people seem to like the red knob Concert Leads more? i'm not finding much info on these heads, it seems like there is more info on Beta Leads?

are Beta Leads more desirable for some reason?

[shibbz]

I believe the silverface concert lead was 150 watts @ 4 ohms, and the red is 200 @ 2.
Also the silverface has 2 independent channels with separate controls for each while the red has 1 with a distortion switch.
I'm not sure about difference in sounds though.

[george]

The "red knob" concert series uses almost the exact same power amp design (transformer coupled quasi complementary output stage) as the "black 0-10" knob design. The former claims 200 W on the rear panel but no mention of impedance. (I have repaired many of these amps where the owner had previously been charge for a "blown" transformer - when only repairs to the bias resistors and output TRANSISTORS were needed - probably because these components over heated/damaged when loaded by 2 ohm loudspeaker combinations.

Input pre-amps of both designs use FETs in the input stages and BJTs in the finals - why would they "sound" differently may be related to the subjective nature of listening tests done in the MI pro sound world.

[John Matrix]

I think that in order to use the reverb on the silverface model you need the footswitch (really hard to find). Could be wrong though, I don't have a silver one.

[Isaac]

IIRC, the reverb was on unless turned off by the footswitch.