Echoplex Preamp Pedals

PLX · Post by **PLX** » Mon Jul 19, 2021 3:52 am

I've had a Badgerplex AC since these pedals first became a thing, about 10 years ago.

Robert at Badger Effects sent me the schematic he used, along with an additional TIS58 transistor.

Out of all the EP-pre pedals out there over the years, the Badgerplex AC is the only one that is using the actual pre-amp section of the EP-3 circuit.

Now here's the Clinch FX version:

The top section is the 18V charge pump circuit. This uses an LT1054 chip to regulate the charge pump to produce 18V from the 9V input.

Whereas the Badgerplex AC uses a 120v primary/24V secondary transformer, full wave rectifier and filter capacitors.. just like the original circuit.

I've highlighted the sections where he deviates from the actual Echoplex 3 circuit. Here's Peter Clinch's explanation :

"..in 2011 I developed a second JFET stage that is totally transparent and lowers the output impedance without changing the classic tone."

Note the addition of the "fat" switch on Q1. This was done to emulate later revisions of the EP-3, having a darker tone.

Badgerplex AC gutshot:

ClinchFX EP-Pre gutshot:

Here's the Chase Secret Preamp pedal:

As you can see, the Chase Secret Preamp is using a charge pump, like the ClinchFX, to achieve an 18V supply rail from a 9V power input.. however there is no additional JFET stage driving the output, as in the ClinchFX EP-PRE.

Note the cheap components used in the Chase product. This was an early version (circa 2012) and his production methods seem to have improved of late.

Post by **RockyStar** » Mon Jul 19, 2021 4:39 am

What about the Catalinbread and Dunlop stuff?

PLX · Post by **PLX** » Mon Jul 19, 2021 4:44 am

RockyStar wrote: ↑Mon Jul 19, 2021 4:39 am What about the Catalinbread and Dunlop stuff?

Gutshot of the Caitlinbread Epoch:

Haven't seen a schematic for this, so I can't comment.. however it appears to be using a charge pump to achieve either 18 or 24V, as well as several additional transistors, which is probably a drive circuit not found in the original Echoplex.

PLX · Post by **PLX** » Mon Jul 19, 2021 5:03 am

Xotic EP Booster:

Same sort of thing going on here where you have an additional transistor to boost the signal.

In the original Echoplex circuit there is only a modest 6dB of gain from the preamp circuit.

Post by **lll** » Mon Jul 19, 2021 5:01 pm

I have the Badgerplex Trilogy (and the 1011, which isn't an Echoplex preamp but Ritchie's AIWA reel-to-reel unit preamp).

Both are awesome sounding.

As mentioned (and to go into a little more detail), Robert's are the only ones who use the true-to-original-circuit TIS-58 running at ~22-24V.

Robert is an awesome dude; unfortunately, he hasn't been doing pedals in a few years.

PLX · Post by **PLX** » Mon Jul 19, 2021 5:26 pm

lll wrote: ↑Mon Jul 19, 2021 5:01 pm I have the Badgerplex Trilogy (and the 1011, which isn't an Echoplex preamp but Ritchie's AIWA reel-to-reel unit preamp).

Both are awesome sounding.

As mentioned (and to go into a little more detail), Robert's are the only ones who use the true-to-original-circuit TIS-58 running at ~22-24V.

Robert is an awesome dude; unfortunately, he hasn't been doing pedals in a few years.

I wish I had gotten a Pre Plural from him.

Two Echoplex pre-amp circuits running in series.

Post by **harddriver** » Mon Jul 19, 2021 5:42 pm

I own a custom Clinch EP-PRE that has a switch to toggle from early to late EP3's and I own a Chase Secret Preamp built to match the later darker sounding EP3 it was the first one he built with an actual TIS-58.

When I compared them both to my EP3 Echoplex I felt the Chase pedal was a more accurate sounding pedal. The Clinch does sound good and has all the attributes but it seemed the Chase was more exact when splitting hairs.

I've heard great things about the Badgerplex as well.

PLX · Post by **PLX** » Mon Jul 19, 2021 6:06 pm

harddriver wrote: ↑Mon Jul 19, 2021 5:42 pm I own a custom Clinch EP-PRE that has a switch to toggle from early to late EP3's and I own a Chase Secret Preamp built to match the later darker sounding EP3 it was the first one he built with an actual TIS-58.

When I compared them both to my EP3 Echoplex I felt the Chase pedal was a more accurate sounding pedal. The Clinch does sound good and has all the attributes but it seemed the Chase was more exact when splitting hairs.

I've heard great things about the Badgerplex as well.

There was some drama back in the day on the old metroamp forum in a thread about these pedals (started by Ben Wise). Peter wound-up getting involved in the thread directly, things got ugly, he then created a sock-puppet account to pile on... things got nasty.

Don Barzini was in on the action. He had some sort of bad experience with ClinchFX, and so he came in - guns blazing.. good times

I've since talked to Peter thru PM over on TGP, and he's a very intelligent and thoughtful person.

He actually gave me a lot of info and pointers on these types of circuits during our discussions.

Post by **harddriver** » Mon Jul 19, 2021 9:49 pm

PLX wrote: ↑Mon Jul 19, 2021 6:06 pm There was some drama back in the day on the old metroamp forum in a thread about these pedals (started by Ben Wise). Peter wound-up getting involved in the thread directly, things got ugly, he then created a sock-puppet account to pile on... things got nasty.

Don Barzini was in on the action. He had some sort of bad experience with ClinchFX, and so he came in - guns blazing.. good times

I've since talked to Peter thru PM over on TGP, and he's a very intelligent and thoughtful person.

He actually gave me a lot of info and pointers on these types of circuits during our discussions.

What was your user ID on Metroamp? I was one of Peter Clinch's first customers of his EP-PRE after he made his prototypes, that was 2007 I think and it still works great and Peter is a really great person, he had some health issues and he got away from building pedals but he was very knowledgeable for sure, Ihaven't emailed him for some time now I hope he is well.

I can't remember when I added the Chase maybe 2013 or so. I have since sold the echoplex and moved to a Boss DD500 instead but if one were to go just for Ed's original tone a real Echoplex is hard to beat, you can get close with these pedals but the real deal just has it for sure.

I even went so far as to run two Clinch EP-PRE's in series as Ed did where he had one EP3 set for a slapback echo and longer 300-400ms echo. The EP3 circuit has an effect on tone for sure.

PLX · Post by **PLX** » Mon Jul 19, 2021 10:05 pm

harddriver wrote: ↑Mon Jul 19, 2021 9:49 pm What was your user ID on Metroamp? I was one of Peter Clinch's first customers of his EP-PRE after he made his prototypes, that was 2007 I think and it still works great and Peter is a really great person, he had some health issues and he got away from building pedals but he was very knowledgeable for sure, Ihaven't emailed him for some time now I hope he is well.

I can't remember when I added the Chase maybe 2013 or so. I have since sold the echoplex and moved to a Boss DD500 instead but if one were to go just for Ed's original tone a real Echoplex is hard to beat, you can get close with these pedals but the real deal just has it for sure.

I even went so far as to run two Clinch EP-PRE's in series as Ed did where he had one EP3 set for a slapback echo and longer 300-400ms echo. The EP3 circuit has an effect on tone for sure.

I had an account at Metro that I created in 2004. Forgot the password and the mods said they couldn't help me, so I created a new account.

That's been so long ago I honestly can't recall. I have been on every guitar gear forum that exists since the days of the old Plexi Palace.

I believe the 2 echoplex's in series was a very real thing in several notable players' signal chains in the 1970's

I'm in the process of building another circuit known to be used by two of my favorite players while in the recording studio (Angus & EVH) .

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