Heritage Amps Channel Crosstalk !

[roger bayliss]

Hi all

Just thought I would mention that the other day when I strummed my Heritage AC30 whilst plugged into the ef86 chl with the volume right down I had sound coming out of the speakers and then realised he top boost volume was up and quickly realised the ef86 was leaking into the top boost chl..

I waggled the guitar lead plug in all the input sockets and it reduced the volume to almost nothing (still a very slight crosstalk though when top boost volume up full) and all appears to be working normally.

Have spoken to Amanda about the problem and the view is that the input jack sockets are the likely reason for this crosstalk should your own amp have similar issue.

Just so you are aware . Does the problem happen on older vintage AC30's AC15's ?

[rogera]

I've worked on quite a few Roger (and played through them) and haven't noticed that problem.

[des mcneill]

Hi Roger,
I have several vintage AC30s, they all do it !!! I understood it was normal but will stand to be corrected.
Des.

[roger bayliss]

Roger

Thanks for comment I respect your knowledge in these things. Maybe you never noticed before as you need the vol right up on one chl and right down on another but maybe the amps you have had have had good jacks on them. The modern amps often made in China do not have the quality in the parts and maybe thats part of it.

Des

At least someone else has noticed and that's with the vintage stuff... I suspect it's the jack plugs either the way they are wired or the design. You can only barely hear the crosstalk with the Top Boost chl vol right up and the ef86 right down but clearly a faint leak into the other chl and initially it was quite loud until I wiggled the jacks in and out a bit !

[peter roest]

I have done some tests with my AC30 TBR (1984), with brilliant channel 1, normal channel 2 an tremolo channel 3. It's remarkable.

Test 1: Playing rhytm guitar plugged in brillant channel;
. Volume pots each channel on zero: Very littlebit sound out of the speakers;
turning on channel 2 on max.: there is clear hearable sound not loud, then turning on channel 3 to max, the soundvolume increase for the bass tones;
turning on channel 3 on (channel 2 =zero) max first gives also hearable sound with lower level.

Test 2: Playing rhytm guitar plugged in normal channel:
. All channel volume pots on zero; There is only some 50/100/150Hz hum hearable;
turning on channel 1 on max. there is clear hearable sound not loud, bass and treble pots are active working, then turning on channel 3 gives more volume;
turning on channel 3 first is the same as in test 1.

Test 3: Guitar plugged into tremolo channel (not playing) : some (radio?) noise is hearable;
turning on channel 1 on max. there is radiosound on the Vox. Putting the guitarcord in a good position, I got clear radiomusic out of the Vox, after this I
didn't turned up channel 2.

I can explain this, but its only for electronica heads

Peter

[des mcneill]

Hi Peter,
You have reminded me of a gig I played in Belfast ,early sixties. The lead and rhythm players used new tan Supertwins and we played a dance hall on the first floor,- unfortunately there was a taxi office underneath. The whole gig we had to endure radio transmissions such as "would you pick up Mrs Smith at The Red Lion bar at 10.30? coming through the rhythm amp. Made for an interesting gig !!! Those were the days.
Des.