Dunlop CryBaby into tansformer

G

Gareth Magennis

Guest
My test bench has for many years had a couple of ground isolated Neve 1:1
transformers between XLR input test sockets and stereo monitors.

Which has never been a problem, but has ALWAYS been a problem connecting any
CryBaby Wah Wah pedal.

If you do, the CryBaby resonates at full volume, behaving much like turning
a VCF resonance control to full, so it self oscillates.
Why is that?

I guess that means you could never directly connect a CryBaby to any
transformer balanced mixer input.




Circuit here:


http://www.electrosmash.com/crybaby-gcb-95



Gareth.
 
Just for giggles, have you tried reversing the plug polarity?

Peter Wieck
Melrose Park, PA
 
wrote in message
news:e3c0123d-c6f9-4d53-ae57-140a34499745@googlegroups.com...

Just for giggles, have you tried reversing the plug polarity?

Peter Wieck
Melrose Park, PA

******************************************************************


No,I thought as it is transformer and ground isolated it shouldn't matter.


Gareth.
 
"Gareth Magennis" wrote in message news:Co6eB.357659$_F5.107046@fx40.am4...



wrote in message
news:e3c0123d-c6f9-4d53-ae57-140a34499745@googlegroups.com...

Just for giggles, have you tried reversing the plug polarity?

Peter Wieck
Melrose Park, PA

******************************************************************


No,I thought as it is transformer and ground isolated it shouldn't matter.


Gareth.




**************************************************************


The output goes into an inductor, the CryBaby doesn't seem to like it.



Gareth.
 
On Wednesday, July 26, 2017 at 3:51:02 PM UTC-4, Gareth Magennis wrote:

No,I thought as it is transformer and ground isolated it shouldn't matter.


Gareth.
Click to expand...

If you have the typical "Hot-Neutral" configuration, it does - well - better stated, it can. It does not matter only with hot-hot configurations such as US 240V single-phase connections. Try reversing, and please let us know.

Peter Wieck
Melrose Park, PA
 
wrote in message
news:96f2aad0-4bc3-4cee-b9d8-081d277f49bb@googlegroups.com...

On Wednesday, July 26, 2017 at 3:51:02 PM UTC-4, Gareth Magennis wrote:

No,I thought as it is transformer and ground isolated it shouldn't matter.


Gareth.
Click to expand...

If you have the typical "Hot-Neutral" configuration, it does - well - better
stated, it can. It does not matter only with hot-hot configurations such as
US 240V single-phase connections. Try reversing, and please let us know.

Peter Wieck
Melrose Park, PA



************************************************************


Hi Peter, I think you have the wrong end of the stick.


This is a guitar effects pedal, a "Wah Wah".
It is a resonant circuit that emphasises mid frequencies to produce vowel
like sounds when played with a guitar.


The "problem" I have always had is that you cannot connect this to a
transformer based pre-amp, as it would seem the inductive load affects the
circuitry in a way that seems to make the resonant circuit resonate like
crazy.
This unit is intended to plug into a guitar amplifier, not a transformer
based test bed, where it misbehaves.



Gareth.
 
Gareth Magennis wrote:

-------------------------
My test bench has for many years had a couple of ground isolated Neve 1:1
transformers between XLR input test sockets and stereo monitors.
Click to expand...

** Are they toroidal, red coloured with black potting in the centre ?

Which has never been a problem, but has ALWAYS been a problem connecting any
CryBaby Wah Wah pedal.

If you do, the CryBaby resonates at full volume, behaving much like turning
a VCF resonance control to full, so it self oscillates.
Why is that?

I guess that means you could never directly connect a CryBaby to any
transformer balanced mixer input.
Click to expand...

** You need an active DI for that job, preferably with JFET input.

Maybe you could add 48V phantom for it to one of the XLRs with two 6.8kohms.



....... Phil
...... Phil
 
Gareth:

I know what it is - I have repaired a number similar devices for my neighbor. I suggest what I suggest due to (limited) direct experience with such devices.

If you try this suggestion and it works, good. If not, no loss.

Next thing to look for would be cold-solders or poor connections - most of what I fixed for my neighbor.

Peter Wieck
Melrose Park, PA
 
"Phil Allison" wrote in message
news:50dde5a8-ded1-43bf-90d7-497a26c63e88@googlegroups.com...

Gareth Magennis wrote:

-------------------------
My test bench has for many years had a couple of ground isolated Neve 1:1
transformers between XLR input test sockets and stereo monitors.
Click to expand...

** Are they toroidal, red coloured with black potting in the centre ?

Which has never been a problem, but has ALWAYS been a problem connecting
any
CryBaby Wah Wah pedal.

If you do, the CryBaby resonates at full volume, behaving much like
turning
a VCF resonance control to full, so it self oscillates.
Why is that?

I guess that means you could never directly connect a CryBaby to any
transformer balanced mixer input.
Click to expand...

** You need an active DI for that job, preferably with JFET input.

Maybe you could add 48V phantom for it to one of the XLRs with two
6.8kohms.



....... Phil




******************************************************************


I always just put it through a guitar amplifier, there is usually one
around.


Oh, I checked today and my bench doesn't actually have Neve transformers, I
used them for another project and got confused/forgot.
They are indeed the orangey coloured toroids with potting in the middle,
with a threaded insert for mounting.

The ones I used on my bench are pretty much the ones BSS used in their AR116
DI boxes.



Gareth.
 
Gareth Magennis wrote:

----------------------------
** You need an active DI for that job, preferably with JFET input.

Maybe you could add 48V phantom for it to one of the XLRs with two
6.8kohms.


******************************************************************


I always just put it through a guitar amplifier, there is usually one
around.


Oh, I checked today and my bench doesn't actually have Neve transformers, I
used them for another project and got confused/forgot.
Click to expand...

** So it used to have Neve transformers or never had them ?

You are an expert at ambiguous posting.


They are indeed the orangey coloured toroids with potting in the middle,
with a threaded insert for mounting.
Click to expand...

** Yes, that is the same kind I have seen recently.


The ones I used on my bench are pretty much the ones BSS used in their AR116
DI boxes.
Click to expand...

** Potted in a Mu-metal box ?

Made by OEP and sold by Farnell ?



...... Phil
 
"Phil Allison" wrote in message
news:70ca723d-a83b-423d-9935-496d9ac1a3fa@googlegroups.com...

Gareth Magennis wrote:

----------------------------
** You need an active DI for that job, preferably with JFET input.

Maybe you could add 48V phantom for it to one of the XLRs with two
6.8kohms.


******************************************************************


I always just put it through a guitar amplifier, there is usually one
around.


Oh, I checked today and my bench doesn't actually have Neve transformers,
I
used them for another project and got confused/forgot.
Click to expand...

** So it used to have Neve transformers or never had them ?

You are an expert at ambiguous posting.


They are indeed the orangey coloured toroids with potting in the middle,
with a threaded insert for mounting.
Click to expand...

** Yes, that is the same kind I have seen recently.


The ones I used on my bench are pretty much the ones BSS used in their
AR116
DI boxes.
Click to expand...

** Potted in a Mu-metal box ?

Made by OEP and sold by Farnell ?



...... Phil


***********************************************************


Sounds pretty likely, I bought them a long time ago.



Gareth.
 
Gareth Magennis wrote:

-------------------------------
** You need an active DI for that job, preferably with JFET input.

Maybe you could add 48V phantom for it to one of the XLRs with two
6.8kohms.


******************************************************************


I always just put it through a guitar amplifier, there is usually one
around.


Oh, I checked today and my bench doesn't actually have Neve transformers,
I used them for another project and got confused/forgot.


** So it used to have Neve transformers or never had them ?

You are an expert at ambiguous posting.


They are indeed the orangey coloured toroids with potting in the middle,
with a threaded insert for mounting.


** Yes, that is the same kind I have seen recently.


The ones I used on my bench are pretty much the ones BSS used in their
AR116
DI boxes.


** Potted in a Mu-metal box ?

Made by OEP and sold by Farnell ?



..... Phil


***********************************************************


Sounds pretty likely, I bought them a long time ago.
Click to expand...

** Look like them ??


http://www.canford.co.uk/Images/ItemImages/large/23-064_01.jpg





..... Phil
 
"Phil Allison" wrote in message
news:cb0e3a2a-7c7b-494b-9e6b-762b0de1796b@googlegroups.com...

Gareth Magennis wrote:

-------------------------------
** You need an active DI for that job, preferably with JFET input.

Maybe you could add 48V phantom for it to one of the XLRs with two
6.8kohms.


******************************************************************


I always just put it through a guitar amplifier, there is usually one
around.


Oh, I checked today and my bench doesn't actually have Neve
transformers,
I used them for another project and got confused/forgot.


** So it used to have Neve transformers or never had them ?

You are an expert at ambiguous posting.


They are indeed the orangey coloured toroids with potting in the middle,
with a threaded insert for mounting.


** Yes, that is the same kind I have seen recently.


The ones I used on my bench are pretty much the ones BSS used in their
AR116
DI boxes.


** Potted in a Mu-metal box ?

Made by OEP and sold by Farnell ?



..... Phil


***********************************************************


Sounds pretty likely, I bought them a long time ago.
Click to expand...

** Look like them ??


http://www.canford.co.uk/Images/ItemImages/large/23-064_01.jpg




************************************************************



Probably decided at the time I didn't really need the mu-metal casing, but
yes, this is the type I got.
Don't know what impedance, but got 1:1 versions.

http://uk.farnell.com/oep-oxford-electrical-products/a262a6e/transformer-audio-1-1-1-1/dp/1689033


The 4 Neve donuts went into a couple of isolator boxes at live gigs.
Still use one box between the live system and the recording laptop /
soundcard.



Gareth.





Gareth
 
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