IgorFX Impedance Buffer: A Review

[rustynuts]

I received the IgorFX Impedance Buffer a couple of weeks ago and have been playing around with it since then to see just how useful it might be. For those of you that don't know, the buffer (or "attenuator" as bongomania refers to it) is produced by TB's very own Toasted.

I have active basses and I love fuzz pedals - all dirt pedals for that matter - so the original intent (and Toasted's suggested usage) was to pick one up to take the edge off of some of my fuzz/active bass combinations. To that end, the IgorFX performs flawlessly; with the buffer the fuzz is mellower, more contained with somewhat better bottom end retention.

And yet I found another useful application for it as well: It can also be used to double the tonal options of your dirt pedals.

The device itself is a simple, straight through signal attenuator with no switch to turn it on and off. It's meant to be run inline between the bass and fuzz pedal(s) in an always-on configuration. There are only the jacks - input, output and 9V - and an LED on top. Me being me, I had to A/B it first to see how much of a difference it really made in my sound so I put it in the loop of one of my Keeley bypass pedals, and that is now where it's going to stay.

It may be the fact that I have developed a guitarist's ear after playing them for so long before turning to bass, but I find that while I like the controlled, mellower fuzz tones with the buffer I also like the raw, gritty, dirty and buzzier tones without it. Some of those raspy tones sync well with my style of playing.

So.....I'm going to keep it on my board in a loop to allow me the option of turning it on and off. It makes one helluva difference with fuzz pedals and while not quite as pronounced with ODs and distortions it does work its magic on those pedals as well.

Given the choice, I would have preferred the buffer to be housed in a slightly larger enclosure to allow for an on/off footswitch and I suggested such to Toasted. He responded that he may be making a "deluxe" version available in a 1590A type enclosure with the switch for a few dollars more. In my opinion it would certainly be worth the added cost to be able to go from mellow and contained to raw and buzzy with the flick of a switch.

Now, a few words about other aspects of the transaction. First, he includes a set of very comprehensive directions with the device which I actually read (I know, that's totally against the man-laws, but....). The reason I read them was because A.) they were there and B.) Toasted included a little Lego skeleton character along with the buffer and I decided to silicone Mr. Skeleton to the top of the casing before I lost him, so I had a few minutes.

And keeping with the IgorFX type theme, the package came wrapped in purple Halloween wrapping paper. The ladies at the post office were tickled by that when I picked it up.

And it looks like I'm going to have to post a pic of it tomorrow....I just dragged out the camera and the battery is dead, can't seem to locate the charger and my cell phone doesn't want to take even a halfway decent picture tonight.

[SpankyPants]

How much?!?!

I was actually just looking at buffers to replace the Hotcake, and so I could throw something in front of fuzzes too. (Ooooh, I'm getting excited!)

[rustynuts]

Oh, damn, How'd I forget that?

Just over $100: 50 British Pounds, shipped to the US. Worth it? To me, yes since it's opened up a whole new dimension for my dirt boxes.

[judas jedermann]

Does this thing do any good for passive basses? And pics please...

[TaySte_2000]

Tiny

[mikeboth]

Hmmm ... what does this device do that adjusting the volume control on your bass doesn't?

BTW, I would call a 'buffer' something that provides a 1:1 inpututput signal ratio, an 'attenuator' something that provides 1:x output ratio, where x < 1 output.

[rustynuts]

I have no passive instruments so I really can't comment. The intent of the buffer is to bring the active bass' signal more in line with the a passive bass' level so I don't know if there would be any advantage at all to using one on passives.

5stringwonder has one as well and has mentioned he'll be adding his views to this thread. Perhaps he has passive basses so he can offer a comparison? As far as pics, you can see his in the bottom image in this post:

Post Your Pedalboard: Part XI, This one goes to eleven!

It's the little box looking thing with the red LED at the bottom right, not on the board in the last picture.

[rustynuts]

Originally Posted by unbeliever

Hmmm ... what does this device do that adjusting the volume control on your bass doesn't?

It actually alters the output more than just the volume. The volume level stays the same in an A/b on/off comparison but the tone/aggressiveness/etc. of the fuzz is significantly different.

BTW, I would call a 'buffer' something that provides a 1:1 inpututput signal ratio, an 'attenuator' something that provides 1:x output ratio, where x < 1 output.

Hence the note relating to bongo's comments. Toasted has named it a "buffer" so that's what I'm referring to it as in this review.

[Toasted]

Originally Posted by unbeliever

Hmmm ... what does this device do that adjusting the volume control on your bass doesn't?

Turning down the volume contol on your active bass doesn't change the impedance of the output signal. This device changes the impedance of the signal to better drive fuzz circuits.

[SpankyPants]

So, is this a buffer or attenuator?

[mikeboth]

Originally Posted by Toasted

Turning down the volume contol on your active bass doesn't change the impedance of the output signal. This device changes the impedance of the signal to better drive fuzz circuits.

Ok, so the device presents a lower impedance to the input of the fuzz then.

[Toasted]

Nearly there, it presents a higher impedance to the input of the fuzz. Fuzzes based on the fuzzface / big muff / tonebender / cheese like a higher impedance signal - a low impedance signal tends to overload the first transistor stage (especially in a fuzz face, this is why the wooley mammoth sounds so bad with active basses).

Originally Posted by SpankyPants

So, is this a buffer or attenuator?

That's an argument of semantics really, Spanky. It raises the low impedance of an active basses output signal to a higher impedance to drive the inputs of vintage fuzz pedals.

[ehque]

Has this been tested with a wooly mammoth? Seems like a strong contender with the Barge Concepts GLZ-1, but that one comes with a more controls and is a bit fiddly if you're only using it as a attenuator.

[irvinz]

so you could use this something to leave in you chain to eliminate the tbp pop noises and such too? =p that would be the right concept aye?

[5stringwonder]

Originally Posted by rustynuts

I have no passive instruments so I really can't comment. The intent of the buffer is to bring the active bass' signal more in line with the a passive bass' level so I don't know if there would be any advantage at all to using one on passives.

5stringwonder has one as well and has mentioned he'll be adding his views to this thread. Perhaps he has passive basses so he can offer a comparison? As far as pics, you can see his in the bottom image in this post:

Post Your Pedalboard: Part XI, This one goes to eleven!

It's the little box looking thing with the red LED at the bottom right, not on the board in the last picture.

Hey Rusty, I'm using active basses too so I won't be able to give an opinion of this with passive basses. Think there probably won't be a significant impact with passive basses.

I actually prefer that the impedence buffer makes my fuzz pedals sound smoother. I bought the buffer mainly because my Woolly Mammoth. It used to react horribly to my active basses - buzzy and bit uncontrollable. First thing I did when I got the buffer was to hook it up to the Mammoth. Must say that I've never heard the Mammoth sound so good. Much smoother sounding fuzz.

I also like that it is in a very small enclosure. It won't take up much space on your board. Especially if you are comparing it to something like the Barge Concepts GLZ-1 / BV-1

There was one issue that I mentioned to Joe (Toasted) in my PM to him. I tried to hook up the buffer in a daisy chain and it didn't power up. Not sure what the issue was. Had no problems with an isolated output from my T-Rex Jr and from a 1 Spot on its own.

All in all, the buffer does what it's supposed to do. If you play active basses, you might want to seriously consider getting one.

Finally, here's some pics of the buffer and the Lego skeleton that Rusty was talking about. Mine's number 5 of 5 that Joe made in the first batch.








Comparison with the VB-Jr. Think the GLZ-1 / BV-1 is the same size. You can see how much smaller it is.

[TaySte_2000]

Originally Posted by SpankyPants

So, is this a buffer or attenuator?

Attenuators are generally adjustable like the ones guitarists use between amps and cabs to get that power tube distortion at low volume.

Since this is fixed impedance I'd call it a buffer, but what difference does it make as long as it works

[rustynuts]

Hey Rusty, I'm using active basses too so I won't be able to give an opinion of this with passive basses. Think there probably won't be a significant impact with passive basses.

I was thinking there probably wasn't much of a difference with a passive bass but thought you might have one to compare to an active.

And mine's number 3 of 5. Still no pics, can't find the charger.

[SpankyPants]

I have a passive bass...

[bongomania]

To clarify the "buffer" versus "attenuator" wording:

I think I actually used the phrase "impedance adjuster", not "attenuator". If I used the word "attenuator", I must have been hitting the crack pipe that morning.

The reason I said (or intended to say) "impedance adjuster" rather than "buffer" is that a buffer is not just a 1:1 device, but in audio it also specifically means a device that converts from high output impedance to low output impedance; whereas the device we're talking about here converts from low z out to high z out. Of course if you look up buffer on Google you'll find a lot of definitions that don't include impedance, but those are not audio design definitions, they are typically definitions used for digital switching systems, cable TV, etc.

OTOH as I noted the last time this came up, it's obvious that the word "buffer" is easier to type and more intuitive-sounding than "impedance adjuster", so if people want to call it a buffer I'd be a fool to stand in their way.

[rustynuts]

I stand corrected, sorry bongo....You did use the term "impedance adjuster". It was another person I was discussing this with at about the same time that used the word "attenuator":

The "technically correct" definition of a buffer is it isolates the signal and reduces the output impedance- but there is no "technically correct" term AFAIK for a device that raises the output impedance. I'd say the most correct description would be "impedance adjuster" or "load corrector" or something like that. But for ease of conversation it doesn't surprise me that non-technically-obsessed people call it a buffer.