EP-3 Echoplex preamp circuit in pedal UPDATE/CLIPS!

[Toad]

I got a email yesterday that my 2 pedals have been shipped. I'll let you all know how they sound when they get here.
Todd

[clinchfx]

Got mine last night Peter. Sounds pretty good. Halfway round the world in 9 businees days? I can't get a letter across the U.S/Canada border in that time.

I know what you mean. It takes longer than that to send a pedal to the other side of Australia.

Enjoy your EP-PRE.

[Toad]

I got my pedals today. Thanks Peter. Took about 9 days. Four of which where in customs. I need to put batteries in them and try them out.
Todd

[clinchfx]

Todd, it's taken me a while to get back here because we've been so busy catching up with the backlog of orders. I guess you've tried the pedals now. Do you have any comments?

Peter.

[bmf5150]

looks like some one copied your design peter..ebay auction number 200476773968

[clinchfx]

looks like some one copied your design peter..ebay auction number 200476773968

They say that imitation is the sincerest form of flattery However, I have yet to see one of these imitations that is exactly the electrical equivalent of the original EP-3 preamp Close, but no cigar

Sadly, very few of us in the pedal business have any real understanding of electronics. I guess I'm lucky to have had Diploma level training in Electronic Engineering and years of experience, some of which involved working with design engineers from whom I learned so much more than I had learned during my training.

There's always more to learn, no matter how much you think you know.

Peter.

[bmf5150]

I hear ya.just thought I would let ya know.

[somethin'else]

Hey, Thanks Peter! and Mandy! Just got mine yesterday, and holy smokes, this thing is just...

Always On!

Love it, it's a great thing you went and made there. Thanks again Peter!

[clinchfx]

Hey, Thanks Peter! and Mandy! Just got mine yesterday, and holy smokes, this thing is just...

Always On!

Love it, it's a great thing you went and made there. Thanks again Peter!

Thanks Dave, I'm glad you're happy with the EP-PRE.

As I've said a few times, when I built the first prototype, I didn't believe that it could sound so good, so I put it aside for a week to allow the "I've just built this so it must sound good" syndrome to wear off When I tried it again, it still sounded special. That's when I started to take a serious look at producing a commercially viable version, robust enough to be used on the road.

By the way, have you read the user manual? You'll notice that, although the recommended power supply is 9V DC centre negative, the maximum power supply is 12V DC. This has always been the case - it's not a recent edit.

Keep enjoying your pedal. The only time I get a chance to play guitar lately is when I'm testing new pedals

Peter.

[somethin'else]

By the way, have you read the user manual? You'll notice that, although the recommended power supply is 9V DC centre negative, the maximum power supply is 12V DC. This has always been the case - it's not a recent edit.

Yes, I did read the user manual, both on your site and in my hand when I received the pedal

Is there a reason for recommending the 9V over the 12V? Would the charge pumps act in a different manner with the change in supply? Or is it 6 and one half dozen either way? Sorry for the newbie question there.

Keep enjoying your pedal. The only time I get a chance to play guitar lately is when I'm testing new pedals

I will! And I guess you need more help to make the pedals so that you can focus more on testing them (playing)! Thanks again.

[clinchfx]

Is there a reason for recommending the 9V over the 12V? Would the charge pumps act in a different manner with the change in supply? Or is it 6 and one half dozen either way? Sorry for the newbie question there.

Dave, the only reason I chose to run with 9V and the charge pump doubler is that most folks have a 9V pedal supply, but relatively few have a 12V or 18V supply. With a 9V supply, the pedal runs internally at a little more than 17V - if you use a 12V supply, it will have an internal voltage of a little more than 23V.

The way we choose our FETs, it makes no measurable or audible difference to the pedal whether you use 9V or 12V. We end up discarding a large number of FETs, which is one of the reasons I chose to find an almost perfect match for the original TIS58 instead of trying too hard to find NOS TIS58s. Another reason is that old semiconductors in TO-72 or TO-92 style plastic encapsulation can also suffer from Tin/Silver migration across the plastic between the leads, creating a leaky transistor or FET. This is one of the most common small signal semiconductor faults I found during my years as a bench repair tech.

The LT1054 charge pump chip that we use can take up to 15V input. We found it necessary to use a Zener to limit the input because the internal voltage would be nearly 30V and the JFET is rated at 25V maximum. The TIS58 is also rated at 25V. Anyway, it's never smart to run any device at its maximum allowable voltage.

And I guess you need more help to make the pedals so that you can focus more on testing them (playing)! Thanks again.

We are going to get Mandy's brother to drill the boxes and send them to the powder coater. That should free up some time while keeping the "hand built" thing happening.

Speaking of playing, Mandy bought me a mandolin last Christmas. Now, whether you like Mandolin or not, the exercise of trying to learn an instrument with different tuning from a guitar has made me finally start to learn to read music properly. Once again, there's always more to learn.

Peter.

[somethin'else]

ah, Thanks for the explanation, Peter. I suppose the 9v might be safer too, in case folks are playing in clubs/venues that have psycho (unconditioned) supply that hops all over the place!? Maybe it's a mute point... Hey, 'preciate it.

No, I'm not gonna admit I like mandolin Unless of course, it's running through an EP-Pre and into a Metro 100 watter! Sounds like a good remedy for all that Space-Age Solderin', have fun with that!

[clinchfx]

ah, Thanks for the explanation, Peter. I suppose the 9v might be safer too, in case folks are playing in clubs/venues that have psycho (unconditioned) supply that hops all over the place!? Maybe it's a mute point... Hey, 'preciate it.

Dave, as long as the 12V is regulated, it shouldn't be a problem, but, as I said earlier, we choose the JFETs very carefully so that they will work properly over a wide range of voltages. Also, I took a "belt and braces" approach to the design, and there's zener protection inside to save the circuit from higher voltages.

No, I'm not gonna admit I like mandolin Unless of course, it's running through an EP-Pre and into a Metro 100 watter!

Death Mandolin

[harddriver]

Bump for a great pedal!

Thanks! Peter! Still loving my two EP-PRE's since I got them!

What is the run down of features on your new EP+ pedal?

[clinchfx]

Bump for a great pedal!

Thanks! Peter! Still loving my two EP-PRE's since I got them!

What is the run down of features on your new EP+ pedal?

Thanks for the bump.

I'm not sure how much to say here for fear of spamming, but the EP+ is a booster that has an EP-PRE followed by another JFET amplification stage (no, the second stage is not a buffer).

I was hoping to have a new EP+ page on our website today, but we have been a little preoccupied with news of flooding in our home city, Brisbane http://www.abc.net.au/news/stories/2011 ... ion=justin

As many here know, we have been travelling through Australia since August 2010 and we are now in Tasmania, Australia's Island state. We still have a house in Brisbane. One son and both daughters live there but it appears that they are not in danger.

We have been using clean solar power to build pedals, but it is now raining here in Tasmania, so it has been necessary to connect to mains power for a few days. While much of the east coast of Australia is flooding, there are bushfires in Western Australia.

As soon as we have an EP+ page on our website, I will make an announcement in the "Business Classifieds and Product Announcements" section here at MetroAmp.

Please spare a thought or prayer or some good vibes for the folks who have lost loved ones and/or property in the floods

Peter.