The EP-PRE, the first (and so far, the only) pedal to accurately capture the essence of the Echoplex® EP-3 preamp, has always had issues with driving low impedance loads, exactly as happened with the EP-3. Some of the EP Pretenders have used buffer circuits to reduce the output impedance of the circuit, while others have made changes to the circuit. Either modification has resulted in reversal of the "magic" phase response of the EP-3 preamp, rendering it as just a generic FET preamp, not an EP-3 preamp.
As a side effect of developing the ClinchFX EP+ and EP+ Custom, we discovered how to reduce the output impedance of the EP-PRE without reversing the phase response of the EP-3 preamp. In fact, this new development slightly enhances the EP-3 effect. As of now, September 2011, the ClinchFX EP-PRE has lower output impedance. All EP-PRE pedals shipped from now will incorporate this improvement without price increase. The original EP-PRE will still be available as a special order.
Peter.
ClinchFX EP-PRE new Development
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clinchfx
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harddriver
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Re: ClinchFX EP-PRE new Development
Hey Peter this new development sounds great and really intrigues me. I was working on a current plexi amplifer build for my older brother and we were testing it out. He had palyed my 68 metro plexi earlier in which I use two of your original EP-PRE pedals and wanted to hear how the EP-PRE would affect his tone on his current plexi amp. We ran in the other room and got one of mine and plugged it in. I would play and he would switch it in and out while I was playing and even though the effect was subtle it was very apparent that sweet something was missing when he turned it off. He switched it on and off many times until he stated, I think I'll get one of those!
I'm also curious as to how the new design will compare to my old 2007-8 models tonewise. If it enhances the EP-3 effect more I may have to spring to a new model, you also have a internal switch inside the new to select later model EP-3's configuration correct?
What is the best way for my brother to contact you for an order?
Thanks,
Mark
I'm also curious as to how the new design will compare to my old 2007-8 models tonewise. If it enhances the EP-3 effect more I may have to spring to a new model, you also have a internal switch inside the new to select later model EP-3's configuration correct?
What is the best way for my brother to contact you for an order?
Thanks,
Mark
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clinchfx
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Re: ClinchFX EP-PRE new Development
Hey Mark, it's great to hear from you. Thanks for the kind comments.
The new low output impedance version of the EP-PRE, on workbench testing, adds a tiny bit more phase shift to higher frequencies, but this would probably be hardly noticeable unless used with a really clean amp. We spent a lot of time A-B blind testing to ensure that the new version sounds just like the previous one. You will hear a difference with a long cable run between the EP-PRE and amp, because the lower output impedance does not lose high frequencies due to cable capacitance. The new one will sound a little brighter in this situation.
Yes, there is a jumper inside to allow selecting the response of the first EP-3 schematic or the later versions that have a little less top end and a slightly different phase response curve.
Our introduction of the lower output impedance version was triggered by a situation where a customer had compatibility issues between the EP-PRE and a custom pedalboard interface. The input impedance of the board interface was low enough to pull down the output of an EP-PRE. We sent him an EP+ which cured the problem. We then found out that there are some other pedals out there that have lower input impedance than is usually expected. After much head scratching, I worked out that reducing the gain of the second stage of the EP+ would give an EP-PRE with lower output impedance.
If you are not having issues with between your EP-PREs and other gear, there is probably no advantage in buying the new version. Anyway, if your brother buys a new one, you can try it before deciding.
It's easiest for us to keep track of orders if your brother can use this email address, mail@clinchfx.com to contact us
There is also a link at the bottom of my posts that will take him to our website where there is a "contact us" page.
BTW, there is a new page on our website - The TxFuzz.http://www.clinchfx.com/txfuzz It is based on a Fuzz Face, but has an output transformer.
Right now we have a small stock of pedals which will hopefully last until we finally return home from our travels within the next few weeks.
If you have any more questions, I'll do my best to answer them.
Peter.
The new low output impedance version of the EP-PRE, on workbench testing, adds a tiny bit more phase shift to higher frequencies, but this would probably be hardly noticeable unless used with a really clean amp. We spent a lot of time A-B blind testing to ensure that the new version sounds just like the previous one. You will hear a difference with a long cable run between the EP-PRE and amp, because the lower output impedance does not lose high frequencies due to cable capacitance. The new one will sound a little brighter in this situation.
Yes, there is a jumper inside to allow selecting the response of the first EP-3 schematic or the later versions that have a little less top end and a slightly different phase response curve.
Our introduction of the lower output impedance version was triggered by a situation where a customer had compatibility issues between the EP-PRE and a custom pedalboard interface. The input impedance of the board interface was low enough to pull down the output of an EP-PRE. We sent him an EP+ which cured the problem. We then found out that there are some other pedals out there that have lower input impedance than is usually expected. After much head scratching, I worked out that reducing the gain of the second stage of the EP+ would give an EP-PRE with lower output impedance.
If you are not having issues with between your EP-PREs and other gear, there is probably no advantage in buying the new version. Anyway, if your brother buys a new one, you can try it before deciding.
It's easiest for us to keep track of orders if your brother can use this email address, mail@clinchfx.com to contact us
There is also a link at the bottom of my posts that will take him to our website where there is a "contact us" page.
BTW, there is a new page on our website - The TxFuzz.http://www.clinchfx.com/txfuzz It is based on a Fuzz Face, but has an output transformer.
Right now we have a small stock of pedals which will hopefully last until we finally return home from our travels within the next few weeks.
If you have any more questions, I'll do my best to answer them.
Peter.