NPD: Chandler Germanium Drive - Holy Cannoli!

bluesholyman

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Ok, I wasn’t sure what to expect with this pedal and while it can go from colored boost to all out raucous germanium dirt, this has got to be one of the best boost pedals I have ever played. I am typically critical of pedals that don’t have an even spread across the range of controls. What I mean is that as you increase “drive” one would expect the amount of dirt to increase evenly. This pedal does not do that. In every review, its widely stated that drive does little to nothing between 1-7 except a very slight coloring - hardly noticeable at volume. Then between 7-9.5 you start to feel the germanium clip and then between 10 - 11 all hell breaks loose. Normally [in my mind] I’d deride a builder who does such things but it does what it does so well I’m like “who cares, it sounds awesome.” Boost Range and “highs” switches are self explanatory.

The feedback control is a 5 position selector that changes the amount of feedback going into the circuit and it affects the volume level as well as feel of signal - almost like its getting compressed as you go from 1-5. To maintain unity one has to futz with drive and the volume knob, unlabeled and conspicuously above the power jacks on the top side of the pedal. Another inconsistency I am willing to overlook (as though anyone cares.)

The last bit of weirdness I’ll cover are the two required isolated power feeds which cannot be fed from a daisy-chained supply. Two supplies, or two isolated outputs from the same supply. What is going on internally is that the pedal is run at 18v and one supply is inverted to reach 18v (+9v - -9v == 18v) A lot of pedals use charge pumps to do this instead and maybe this is how they did it in the “olden days” or how its done where the case allows room for components, etc., such as the kind of equipment Chandler typically builds (studio rack gear.)

For as much oddity as this thing has, it is the best colored boost I have ever played (comparing to likes of 65 Amps Colour Boost, Aluminum Falcon (chapter/verse klon clone) and maybe something else I am not remembering.

I have put this at the very front of my signal chain and it does delicious wonders with the guitar signal - zero regrets on the purchase. I will probably use it more on single coils and not on ‘buckers unless I want a bit of extra kick there - it kicks nicely, depending on how it is set.

I doubt this is most peoples cup of tea because of price, 2x power requirements, and size. However, if you want a killer boost with some germanium goodness, I cannot recommend this thing enough.

0E34F99A-E5FE-49BD-9F8F-45260707B9B9_1_201_a.jpeg
 

11 Gauge

Doctor of Teleocity
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Interesting...

Here's what it looks like, under the hood:

chandler_germanium_drive_02_1400x.png


...And the black box looks like it's literally just that - a box filled with epoxy that has 6 pins that attach it to the PCB:

chandl12.jpg


...Which makes me wonder how would you service it, if a transistor were to die?

Very odd power setup, but it does eliminate the need for a charge pump.

Anyway, kudos on the find!
 

hotcoffeenochill

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I just traded one of those away recently. Loved it for tones, but I don't do any studio work and it's size, shape, positions of the footswitch and master volume, and power requirements made it more of a burden than it was worth for my gigging board. If I were in to recording or studio work, I'd keep one laying around for sure.
 
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bluesholyman

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And the black box looks like it's literally just that - a box filled with epoxy that has 6 pins that attach it to the PCB:

I wonder if they took that from one of their germanium mic pre's and then used external circuitry to make it compatible with guitar levels.

...Which makes me wonder how would you service it, if a transistor were to die?

I guess they just pop in a new black box and bury the old ones in concrete :D
 

11 Gauge

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I wonder if they took that from one of their germanium mic pre's and then used external circuitry to make it compatible with guitar levels.

I saw some pics of a few different Chandler rack effects that it looks like they have similar black boxes in them.

5ff0be16c6a440cb1e5e4f8664cf6896.png


chandler_germanium_tone_control_03.png


chandler_little_devil_pre_amp_02__08256.1453920619.jpg


chandler_germ_500_MKII_pre_amp_02.jpg


So yeah, it looks like whatever is contained in the box is basically the bulk of the preamplifier parts. It may be possible that we're assuming it contains germanium transistors, when it could very well be silicon ones with germanium diodes.

If those power transformers get warm at all (particularly for what's seen in the bottom two pics), that simply wouldn't work well with germanium transistors.

So if the boxes do indeed contain germanium diodes, that's not really a problem, since failures are rare.
 

schenkadere

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Ok, I wasn’t sure what to expect with this pedal and while it can go from colored boost to all out raucous germanium dirt, this has got to be one of the best boost pedals I have ever played. I am typically critical of pedals that don’t have an even spread across the range of controls. What I mean is that as you increase “drive” one would expect the amount of dirt to increase evenly. This pedal does not do that. In every review, its widely stated that drive does little to nothing between 1-7 except a very slight coloring - hardly noticeable at volume. Then between 7-9.5 you start to feel the germanium clip and then between 10 - 11 all hell breaks loose. Normally [in my mind] I’d deride a builder who does such things but it does what it does so well I’m like “who cares, it sounds awesome.” Boost Range and “highs” switches are self explanatory.

The feedback control is a 5 position selector that changes the amount of feedback going into the circuit and it affects the volume level as well as feel of signal - almost like its getting compressed as you go from 1-5. To maintain unity one has to futz with drive and the volume knob, unlabeled and conspicuously above the power jacks on the top side of the pedal. Another inconsistency I am willing to overlook (as though anyone cares.)

The last bit of weirdness I’ll cover are the two required isolated power feeds which cannot be fed from a daisy-chained supply. Two supplies, or two isolated outputs from the same supply. What is going on internally is that the pedal is run at 18v and one supply is inverted to reach 18v (+9v - -9v == 18v) A lot of pedals use charge pumps to do this instead and maybe this is how they did it in the “olden days” or how its done where the case allows room for components, etc., such as the kind of equipment Chandler typically builds (studio rack gear.)

For as much oddity as this thing has, it is the best colored boost I have ever played (comparing to likes of 65 Amps Colour Boost, Aluminum Falcon (chapter/verse klon clone) and maybe something else I am not remembering.

I have put this at the very front of my signal chain and it does delicious wonders with the guitar signal - zero regrets on the purchase. I will probably use it more on single coils and not on ‘buckers unless I want a bit of extra kick there - it kicks nicely, depending on how it is set.

I doubt this is most peoples cup of tea because of price, 2x power requirements, and size. However, if you want a killer boost with some germanium goodness, I cannot recommend this thing enough.

View attachment 1078914
love the toggles...very useful.
 

middy

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You can’t patent an electrical circuit, but you can hide it. It’s their prerogative to slow down copycats if they feel like it’s worth the effort.
 

bluesholyman

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You can’t patent an electrical circuit, but you can hide it. It’s their prerogative to slow down copycats if they feel like it’s worth the effort.

Yeah, if you make it hard enough, most won't even try. Not saying it would happen, but if this drive (or any other for that matter) were to gain notoriety like the Klon (or the Dumble,) someone my spend time to try to deconstruct the magic and reproduce it. But, as much as the KoT has been copied, people still want the original. While I don't believe in magic diodes and unicorns. I am sure that a certain combination of very specific parts well chosen, leads to the magic that some of these things do and a cheap copy, even if all same values, won't sound exactly the same or perhaps as good.

As a studio device, its killer, not so much so on a live rig as @hotcoffeenochill lamented above. Only thing that I recall being "like" this as a clean boost is the Hughes/Kettner Tube Factor. It was twice the size and even more juice (ran the tube at proper voltage with real AC adapter, not DC.) But that was too much trouble. This one might be the sweet spot for me.
 

middy

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This is bending the definition of boost to include “wacky preamp with fuzz”. All in the fine tradition of the treble booster…

I bet a Showman rack preamp like some bass players use would be a great “boost”, too. Driving some 12AX7s at high voltage with toroidal transformers.
 

RetroTeleRod

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Someone ought to write a song, "Black Box Blues" from the point of view of a guy trying to steal a pedal circuit but it's potted in epoxy inside a black box.
That woman of mine done stole my Klone

Left me broken hearted and with no tone

She really thought it was a real gold Klon

When she hit the road and went moving on



The pawnshop laughed her out of the store

Offered ten dollars and not a penny more

That’ll teach her to take a man’s buffer

and leave him all alone to suffer



Got them mean ol’ Black Box Blues

My pedal man gave me the sad sad news

There’s too much goop on the circuit Son

No way to build you another one



No woman, no pedal and a broken string

My life just don’t mean a thing

But I heard a rumor from a drummer and a diver

‘Bout a deal on a used Blues Driver
 
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11 Gauge

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@11 Gauge. If germanium transistors were wired to be used as clipping diodes (body diode?), would proximity to heat still be a factor?
I actually just educated myself on the subject, never really giving Ge diodes specifically much thought about this.

With Ge diodes, the forward voltage does indeed rise as they get warmer. This just equates to them possibly sounding closer to your typical Si diode.

With Ge transistors, the gain increases as they get warmer, which causes the bias to change, which really effs up the sound.

So transistor wired as a diode, there should be a relatively small noticeable difference, provided the forward voltage rises enough (probably an increase of maybe 80mV or greater). Many Ge diodes seem to measure in around 400mV or so, while something like a 1N400X is probably a little north of 500mV, so maybe a really warm 1N34A might sound like a 1N400X?
 
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