Fuzz and clean DI problem

[Sausage]

I do recall that a pedal like the original Fuzz face does things to the signal. I remember problems trying to run a Fuzz before a crybaby. Like it doesn't feed the crybaby the full signal or something. Its been a while so maybe someone else can elaborate on this. Perhaps the easiest thing to do is to get some kind of loop pedal. Keep the Fuzz in a loop and just kick the loop in when you need it. I also seem to remember something about using a buffer. If you have another pedal, put it between the Fuzz and your preamp. That will reboost or buffer the signal up again. It can be just about any pedal you have lying around. That should definitely help. This problem you are experiencing is common with Fuzz Face type boxes, and a Fuzz seems to be the only pedal that presents this problem. I am pretty sure you always have to run a Fuzz type pedal first in the chain. It wants to have an input direct from the guitar. Again A loop pedal would be the most logical choice, but the loop should a passive loop.

[Eurooppa]

Thank you Sausage, but you missed the problem.
It's not the fuzzed signal I'm having problems with, but the clean signal that's been split before the fuzz and going in to another input on my audio interface.

Switching the fuzz on and off is not a solution since it's my main signal.
The clean DI is for possible re-amping purposes.

[stafs]

I had similar problem when i was recording JCM900 amp. I splitted the signal with DI box, using its parallel out (to amp), and clean signal was sent to audio interface via Xlr. When gain channell on JCM900 was used, the clean DI signal distorted badly. I never had that problem before with any other amp. In my case changing DI box solved the problem. Maybe borrow active (!) DI box, to check the splitting stage of Your setup.

[Sausage]

Originally Posted by Eurooppa

Thank you Sausage, but you missed the problem.
It's not the fuzzed signal I'm having problems with, but the clean signal that's been split before the fuzz and going in to another input on my audio interface.

Switching the fuzz on and off is not a solution since it's my main signal.
The clean DI is for possible re-amping purposes.

My apologies. I didn't read your post properly. A Fuzz pedal is very low impedance and it will load your pickups heavily. It is effectively pulling down your guitar signal and affecting the other output that is going to your recording interface. It does seem hard to believe that it would do this as your Lehle has an isolation transformer, but that is the nature of a Fuzz box. I am pretty sure you can put any other pedal in place of the Fuzz and you will not have a problem with your signal to your interface. One thing you can try is to try an active A/B/Y box as suggested above, and see if it does the same thing. But the Fuzz will probably not like a buffered signal and it will not sound right. It is unbelievable that you have such a simple (and cool) setup but you happen to like the one box on the planet that does not play nice with anything else. It wants to be the first thing you plug your guitar into. One last thing you can try is to put a pedal (any Boss, Ibanez...)between the Lehle and your recording interface. This may buffer your signal up again and give you a stronger signal into your interface. I hope you can find a solution.

[Eurooppa]

Thanks again Sausage and stafs.
Trying out these new ideas one by one...
In my case switching the preamp to a clean channel ( or another / third dist. channel ) didn't make any difference - same symptoms on the DI signal as previously.

Inserting a Boss HM2 pedal between the p-split and audio interface also didn't make any difference.

Have to try an active DI-box next...

Anybody have any experience on DI-boxes with an impedance load correctors such as Radial JDV?

[drbob1]

I'm not sure it's a problem with the input impedance of the Fuzz Factory, I believe that has a VERY high input impedance.

Do you have the same problem with other gain pedals instead of the fuzz (overdrives like a TS9 for example)? If the fuzz is bypassed there's no problem, right? Is your guitar an active or passive output (is there a 9v battery in there?).

[Eurooppa]

To drbob1:
Yes, I have the problem only with the fuzz pedal and it does go away when fuzz is bypassed.
Pickups are passive.

[Sausage]

Originally Posted by drbob1

I'm not sure it's a problem with the input impedance of the Fuzz Factory, I believe that has a VERY high input impedance.

Do you have the same problem with other gain pedals instead of the fuzz (overdrives like a TS9 for example)? If the fuzz is bypassed there's no problem, right? Is your guitar an active or passive output (is there a 9v battery in there?).

The Fuzz factory has a very LOW input impedance, like most Fuzz type boxes. That is why it loads down the guitar and is sucking all of the juice from his pickups. Unfortunately a Fuzz pedal is one of the rare pedals that does this. It wants to be the first pedal in the chain and wants to be plugged directly into a guitar. He will probably not have any problem if he replaced the Fuzz with any other pedal. But then he loses his cool tone. Nothing you can do really but buffer the other signal going to his interface. The weak signal left after the Fuzz hogs it all may be able to be boosted up to usable levels with any simple stomp box plugged in the chain before his interface. It can be set to bypass but hopefully the buffer in the stomp box will be able to boost his signal up to a reasonable level for his interface. Please try this and let us know how it works.

[foldback]

Originally Posted by Sausage

The Fuzz factory has a very LOW input impedance, like most Fuzz type boxes. That is why it loads down the guitar and is sucking all of the juice from his pickups. Unfortunately a Fuzz pedal is one of the rare pedals that does this. It wants to be the first pedal in the chain and wants to be plugged directly into a guitar.

Sorry, I must completely disagree with your specification about the input impedance being very low, if you can supply actual data otherwise then I apologize but your characterization is exactly opposite of transistor theory. Solid state circuits have very low output impedance and that is what does not work well driving into a germanium fuzz box.

I looked for exact tech specs on this piece but the manufacturer does not provide them.

FOR THE OP
Since your splitter box is passive and it has a transformer in it I'm going to say that driving that is what is loading down the guitar. I use a Radial Tonebone to split to two amps and when I use four amps I use the Voodoo lab amp selector, both of these are active and have isolated outputs but you won't get the exact right sound with a Germ fuzz, the only way to make that sound like Hendrix is to drive it as the first device directly from the pickups, if you parallel a transformer input passively across the passive guitar pickup output too you'll pull the overall impedance the guitar pickup is seeing down to under 20k and it's gonna suck tone!

The input of a Geranium fuzz is looking for a pickup-like impedance (6 to 12K ohms), the actual input impedance of the fuzz circuit is over 100K typically. Solid state buffers have very low output impedances and the input to the Germanium fuzz does not like being fed with that (easy to hear the tone change).

I have a Strat that I brought the three pickups out on different jacks for this recording situation in the studio, one pickup can drive the fuzz input and another pickup can drive the D.I. for reamping.

You can fit two Strat pickups in the same cavity as one large humbucker, that can give you an isolated output for the germanium fuzz.

Germanium fuzz boxes are strange beasts, I gave up on them when I found my ultra sweet Maxon green overdrive pedal.

Good luck and good music to all.

[Sausage]

Originally Posted by foldback

Sorry, I must completely disagree with your specification about the input impedance being very low, if you can supply actual data otherwise then I apologize but your characterization is exactly opposite of transistor theory. Solid state circuits have very low output impedance and that is what does not work well driving into a germanium fuzz box.

I looked for exact tech specs on this piece but the manufacturer does not provide them.

FOR THE OP
Since your splitter box is passive and it has a transformer in it I'm going to say that driving that is what is loading down the guitar. I use a Radial Tonebone to split to two amps and when I use four amps I use the Voodoo lab amp selector, both of these are active and have isolated outputs but you won't get the exact right sound with a Germ fuzz, the only way to make that sound like Hendrix is to drive it as the first device directly from the pickups, if you parallel a transformer input passively across the passive guitar pickup output too you'll pull the overall impedance the guitar pickup is seeing down to under 20k and it's gonna suck tone!

The input of a Geranium fuzz is looking for a pickup-like impedance (6 to 12K ohms), the actual input impedance of the fuzz circuit is over 100K typically. Solid state buffers have very low output impedances and the input to the Germanium fuzz does not like being fed with that (easy to hear the tone change).

I have a Strat that I brought the three pickups out on different jacks for this recording situation in the studio, one pickup can drive the fuzz input and another pickup can drive the D.I. for reamping.

You can fit two Strat pickups in the same cavity as one large humbucker, that can give you an isolated output for the germanium fuzz.

Germanium fuzz boxes are strange beasts, I gave up on them when I found my ultra sweet Maxon green overdrive pedal.

Good luck and good music to all.

A simple google search of "Fuzz Face input impedance" Should lead you to many links that can explain it in much better terms than I could ever hope to. Perhaps you should read them and post your theories. Here is one result for example.

Pickup loading. This is a very important aspect in the creation of a great fuzz sound, but not one that people usually think about. Most fuzz pedals typically have very low input impedances.

I don't think the input is 100k as you have suggested. However most other pedals seem to have 100k input impedance.

There seems to be confusion with terminology as to what the input of the Fuzz is seeing and what the actual input of of the Fuzz circuit is. For example A passive guitar puts out about 10k which is considered high. However that same 10k is considered low for a pedal like the Fuzz Face, because pedals normally have 100k. Perhaps you can clear this up.

I don't think it is his Lehle that is causing such a drastic drop in the signal going to his interface. And I am guessing that it is the Fuzz that is loading down his guitar. As I suggested if he replaces his Fuzz with any other 9 volt stomp box I am pretty sure he will not have a problem. I suppose the only way to find out is if the OP tries it and posts his results. Thanks.

[Eurooppa]

With his permission here's what Zack ( from Zvex, manufacturer of Fuzz Factory ) emailed me when asked the same questions:

Hi,

There is no solution to this problem. And after 18 years, you are one
of only two observers of this problem, the first being Chuck Zwicky,
designer of the Woolly Mammoth.

The input impedance of most fuzzes is crap. Very very low. The fuzz
face is bad, the fuzz factory is worse. They drag the signal into the
dirt and smash it flat. There is nothing left. And there is no hope
for an improved situation... that's just the way fuzz is. If you try
to buffer the signal before the fuzz, you will lose fuzz quality.

This is a bit like Schrödinger's cat or Heisenberg's uncertainty
principle. Simply by putting a fuzz into the equation, information is
instantly lost. There is no clean signal anymore. I estimate the
input impedance of most fuzzes to be in the low thousands of ohms.
The output impedance of most guitar pickups is in the gig-ohm range.
Hence the destruction of any clean signal.

I'm sorry to leave you with the sad analysis of this situation, that
you will never have a clean signal and a fuzz signal at the same time.

Rock on, and sorry about the trouble,

Zack

[Sausage]

Originally Posted by Eurooppa

With his permission here's what Zack ( from Zvex, manufacturer of Fuzz Factory ) emailed me when asked the same questions:

Hi,

There is no solution to this problem. And after 18 years, you are one
of only two observers of this problem, the first being Chuck Zwicky,
designer of the Woolly Mammoth.

The input impedance of most fuzzes is crap. Very very low. The fuzz
face is bad, the fuzz factory is worse. They drag the signal into the
dirt and smash it flat. There is nothing left. And there is no hope
for an improved situation... that's just the way fuzz is. If you try
to buffer the signal before the fuzz, you will lose fuzz quality.

This is a bit like Schrödinger's cat or Heisenberg's uncertainty
principle. Simply by putting a fuzz into the equation, information is
instantly lost. There is no clean signal anymore. I estimate the
input impedance of most fuzzes to be in the low thousands of ohms.
The output impedance of most guitar pickups is in the gig-ohm range.
Hence the destruction of any clean signal.

I'm sorry to leave you with the sad analysis of this situation, that
you will never have a clean signal and a fuzz signal at the same time.

Rock on, and sorry about the trouble,

Zack

Straight from the horses mouth. How kind of him to give you such a detailed reply. I must admit I am starting to get confused with all of these ohm values. I didn't know (or understand) that the output impedance of a guitar was in the gig-ohm range. I guess you need to forget about your direct signal and record your amp with a microphone and live in Fuzz heaven.

[Sausage]

Euroopa could you please try to put a pedal between the second output of the Lehle and your interface. I still think there is a small chance that that it may be able to grab what is left of your signal and buffer it up a bit. It just may be useable. Please post your results.

[Eurooppa]

Sausage:
I already tried that as stated in the post #6. Made no difference.

[foldback]

Originally Posted by Sausage

A simple google search of "Fuzz Face input impedance" Should lead you to many links that can explain it in much better terms than I could ever hope to. Perhaps you should read them and post your theories. Here is one result for example.

Pickup loading. This is a very important aspect in the creation of a great fuzz sound, but not one that people usually think about. Most fuzz pedals typically have very low input impedances.

I don't think the input is 100k as you have suggested. However most other pedals seem to have 100k input impedance.

There seems to be confusion with terminology as to what the input of the Fuzz is seeing and what the actual input of of the Fuzz circuit is. For example A passive guitar puts out about 10k which is considered high. However that same 10k is considered low for a pedal like the Fuzz Face, because pedals normally have 100k. Perhaps you can clear this up.

I don't think it is his Lehle that is causing such a drastic drop in the signal going to his interface. And I am guessing that it is the Fuzz that is loading down his guitar. As I suggested if he replaces his Fuzz with any other 9 volt stomp box I am pretty sure he will not have a problem. I suppose the only way to find out is if the OP tries it and posts his results. Thanks.

An even better simple google search for Fuzz Face Schematic revealed the true answer.

Fuzz Central -- Arbiter Fuzz Face

Look at the schematics and you will see that the input signal in the original model comes in on the wiper of a 500,000 ohm pot. This means that the input impedance changes and this changes the "load" the guitar pickups are looking into. With the pot all the way ON the input impedance will be 500,000 ohms (high impedance). When the pot is turned down it can lower the impedance all the way down to lower than the output impedance of the guitar pickups.

On later reissues they lowered the pot value to 100,000 which puts an even greater load on the output of the guitar and probably explains a lot about why the reissues don't sound like the originals, they load your guitar down more.

Lets assume a reissue Fuzz Face with an input impedance of 100,000 ohms (when input control is wide open) and lets consider a Jensen 12:1 direct box transformer with an input impedance of 140,000 ohms, when you parallel these inputs (by going thru the jacks on the DI box) the impedance the guitar will see is going to be much lower than 100,000 ohms (approx 58333 ohms) and the lower it goes the more the tone of the guitar pickup will be changed for the worse. So if the input level control on the fuzz was only about 10% of the way ON and we assume it's a log type pot (approx 20% of total pot value at 10% excursion) then you would be paralleling 20000 ohms and 140000 ohms for a total load to the guitar pickups of approximately 17500 ohms, that's a very low impedance for a passive guitar pickup to look into, the voltage output will collapse significantly and the tone is going to have a lot of high frequency removed as a result.

Here is the formula for combining two impedances: Parallel: RT = (R1R2)/(R1 + R2)
Here is more engineering data to consume if you want more knowledge: http://pr.erau.edu/~newmana/imped.html

Here is this from the Seymour Duncan guitar pickup web site:

Pickups can generally run from 2.5 K to 20 K DC resistance on average.

726-750 - Seymour Duncan

A guitar pickup is a very feeble producer of electricity, it makes voltage but not current. For the pickup tone to NOT BE CHANGED by the load it's connected to the input impedance of the load should ideally be ten times the output impedance of the guitar pickup.

You don't need to get a degree in electrical engineering to learn a few things about combining impedance and loads, John Worams "Recording Studio Handbook" was dealing with these issues back in the 70's.

No clue where the fuzz builder got his impedance ideas but I'm always open to learning.

From the Boss website, I looked at the classic DS-1 Distortion pedal and found the input impedance to be 470,000 ohms (high) and the output imedance to be 1000 ohms. 1000 ohms is low in terms of tube amps but rather high in solid state world, I'm guessing they specified 1k because they want you to not drive it into anything lower than 10K (which is 10x the 1k output impedance). Tascam did this a lot with their specs, they would show the output impedance to be 10k even though if you looked at the schematic you'd see it was actually much lower, they kept the spec high because the unbalanced -10dBv outputs were incapable of driving into the +4dBm inputs of pro equipment made in the 70's and 80's.

The original Tube Screamer (designed in 1979-1980 by S. Tamura, a Japanese Engineer working for Nisshin Onpa/Maxon) has an input impedance of approximately 500000 ohms also. Note that a high output Seymour Duncan humbucker with an output impedance of around 14000 ohms would be very happy driving into 500000 since 10x the 14k pickup output impedance is only 140000, far below the 500k input impedance.

If you plug two stomp boxes (that have 500k input impedance each) in series and if they don't have true bypass switches then the combined impedance the guitar pickup will see is still 250k which is higher than the 140000 we calaculated previously. Now, plug four of these stomp boxes in series and the combined load to the guitar drops to 125k, now we're below the 140k and we're going to start hearing rolloff in the highs and overall less clarity from the pickup. Hope that helps you understand "loading down the pickups".

All this impedance stuff is moot if you have a guitar with active pickups on it, in that case the solid state output will natively be very low impedance and probably be brought up by a series resistance of some sort. An active pickup should have no problem driving a load impedance as low as 10000 ohms, perhaps lower.

Good luck and good music to all.