Weird problem with my EHX Soul food

Russ

I've had my soul food for a few weeks now and I love it, but it's developed a strange problem, when I'm bending notes high up the neck the sound suddenly fades away and goes all muffled! I've tried different cables, a different guitar, isolated it from other effects and ran the amp and guitar without the pedal and different cables. Could it be my amp doesn't like being driven by a pedal? It's an original Blackstar HT5 on the clean channel. I've also got a tc spark booster that I run on the clean channel but this is fine, any ideas?!

Dave_Mc

That happens with some od pedals (kind of like the sustain is wonky, right? the sound just dies away suddenly)- but i always thought I heard (possibly incorrectly) that it happened more with ones with the clippers in the feedback loop rather than hard-clipped to ground as in the soul food. Unless maybe it's interacting with the solid state stuff in the ht5's preamp? (assuming I'm not just incorrect in my assumption about the clipping style of the pedal affecting it) EDIT: and that's not to say there might not just be something wrong with the pedal. i haven't noticed it with mine, but i don't use it all that much.

jpttaylor

I had the HT5 combo a few years ago and whilst I've heard that Blackstar amps take pedals fairly well, the clean channel on mine was a bit picky with some. The flatter the EQ response from the pedal, the better it responded. The mid boost in the Soul Food might be having an impact in that way.

Alternatively, it could entirely be the fault of the pedal. Have you got any other amps to test the pedal with?

Russ

Dave_Mc said:

That happens with some od pedals (kind of like the sustain is wonky, right? the sound just dies away suddenly)- but i always thought I heard (possibly incorrectly) that it happened more with ones with the clippers in the feedback loop rather than hard-clipped to ground as in the soul food. Unless maybe it's interacting with the solid state stuff in the ht5's preamp? (assuming I'm not just incorrect in my assumption about the clipping style of the pedal affecting it) EDIT: and that's not to say there might not just be something wrong with the pedal. i haven't noticed it with mine, but i don't use it all that much.

You are spot on with your description, the sustain just dies away, it seems to be when the drive is just past 12 o'clock.

Russ

jpttaylor said:

I had the HT5 combo a few years ago and whilst I've heard that Blackstar amps take pedals fairly well, the clean channel on mine was a bit picky with some. The flatter the EQ response from the pedal, the better it responded. The mid boost in the Soul Food might be having an impact in that way.

Alternatively, it could entirely be the fault of the pedal. Have you got any other amps to test the pedal with?

I should have said mine is the combo too. I've had loads of different pedals in the past without a problem. The clean channel can be a bit 'spiky' with stuff going in the front end. The problem with the soul food has only just started over the last couple of days though. Could it damage my amp?

Adam_MD

It shouldn't damage the amp.  Can you try the pedal with someone elses amp to see if it still does it?  At least you would know if the pedal was faulty or not.

Russ

I haven't got another amp, and I don't know anyone else who plays the guitar!! Lots of guitars, lots of pedals but only one amp!

ICBM

If you don't have another amp, try plugging the pedal straight into the amp's FX return - that will bypass the preamp, only the channel volumes will work. You will need to plug a spare cable into the amp's input to turn the mute circuit off. If it still does it it's most likely the pedal since the circuit after the FX loop is completely different from the one at the normal input.

In fact if the pedal is an EH, it's most likely the pedal...

Russ

ICBM said:

If you don't have another amp, try plugging the pedal straight into the amp's FX return - that will bypass the preamp, only the channel volumes will work. You will need to plug a spare cable into the amp's input to turn the mute circuit off. If it still does it it's most likely the pedal since the circuit after the FX loop is completely different from the one at the normal input.

In fact if the pedal is an EH, it's most likely the pedal...

That sounds like a good idea, I'll try tomorrow, so if I understand you right I plug my guitar into the pedal input, pedal output to fx return?

ICBM

Russ said:

That sounds like a good idea, I'll try tomorrow, so if I understand you right I plug my guitar into the pedal input, pedal output to fx return?

Yes, and put a second lead (not connected to anything) into the amp's input jack.

Russ

@ICBM Thanks, I tried it and rather frustratingly the pedal worked fine. I plugged it back into the front end and the problem was there still. After a bit of messing about I've found that it's just the neck pickups on my firebird and SG that it happens with, the bridge pickups work fine, the sound is like rolling your tone control all the way off and then a bit more! I'm a bit lost now, is the pedal faulty or just not a good match for my amp?

ICBM

It sounds like the problem is with the match between the pedal and the input of the amp. If it worked fine into the FX return, there's nothing wrong with the pedal itself.

What's probably happening is that the pedal combined with the bass frequencies from the neck humbucker is producing enough level to overload the amp's input - they do have a couple of diodes there to protect the input stage from excessive voltage so it may be those, or it may be overloading somewhere further on in the circuit.

I have heard several reports of the Blackstar HTs not liking some pedals - it seems to be mostly fuzzes but it sounds like we may have to add this one to the list .

Russ

@ICBM Thanks for your help. So now I'm left with a pedal I really like but can't use!

ICBM

Russ said:

@ICBM Thanks for your help. So now I'm left with a pedal I really like but can't use!

Does it do it if you put a buffered pedal (eg any kind of Boss, even if its turned off) after it and before the amp? If it's purely a signal level problem that might not help, but if there's some other odd interaction it might.

Russ

@ICBM I'll try that, I've got a boss Dn2 gathering dust, would switching the buffer on in the soul food do anything?

Russ

Boss didn't work, tried it before and after the soul food.

Dave_Mc

ICBM said:

I have heard several reports of the Blackstar HTs not liking some pedals - it seems to be mostly fuzzes but it sounds like we may have to add this one to the list .

Yeah that's one of the reasons why I don't like Blackstar's advertising which strongly implies (IMO) that they're regular all-tube amps- dirt and boost pedals might not react the way you expect.

Russ said:

@ICBM I'll try that, I've got a boss Dn2 gathering dust, would switching the buffer on in the soul food do anything?

Wait to see what ICBM says, but I doubt it. That being said I have the buffer on in mine since I like its buffer.

ICBM

Russ said:

Boss didn't work, tried it before and after the soul food.

Damn… it sounds very much like some sort of level or frequency issue causing the amp to overload in a way which stops it amplifying the whole audio range properly. Try the buffer in the EH as well, but like Dave says I doubt it will work either.

If that doesn't work the only thing I can think of would be to deliberately reduce the level quite a lot between the pedal and the amp - eg with a volume pedal - and then turn the amp up more to give the same final volume.

Teetonetal

Have you tried activating the soul foods own buffer to see if that helps (internal switch)? It solved some weird clock ticking thing I used to get on mine.

not the same amp, but I have run mine into the front end of an HT40 and there are no issues on any channels.

Russ

@TEETONETAL I've not had chance to try it yet, does it suck much tone when the pedal is off?

Teetonetal

none. 

Buffers sucking tone is one of those guitar players internet myths...