Arion SCH1 (grey one) with CLOCK NOISE after TB mod

[bolsonero]

Hi to all.
I´m very glad od stay into this forum. And I´d been reading along the years very interesting notes, questions, answers...
Well, it´s time to say HELP! with my nice arion sch1. I love that pedal and wanted to upgrade the sound, because it has an awful buffer that ruin your tone. So I did the true bypass mod, but became a thick clocking sound that cannot repair.
I tested all the electrolytic caps without a solution. I´d been reading somo similar problems with other users but before to destroy it I want to have a new chance to solve this problem.
Anyone that can help me to solve it?
Many thanks!!

Sorry for my poor english, because it´s not my lenguage.

[Mark Hammer]

1) What is so bad about the existing buffer?  Do you know that it affects the tone, or did you simply hear from others that it is bad?

2) You might be able to replace the transistor that provides the input buffer with a different one.  For instance I think it may be possible to replace the existing BJT transistor with a FET. 

3) You might be able to replace the dual op-amp used for the output mixing/buffer stages with a "better" chip (e.g., TL072)

4) Be sure that you are not running any wires close to the board.  You might want to try some shielded cable if you are only using single-conductor wire right now.

[Les Turnbull]

The Arion is normally a great sounding chorus and better sounding than a lot of the modern stuff . Give it the once over first as my old Arion Stage tuner went lame for a while but a retighten of the PCB screws and a clean of the spring that earths the PCB to the base plate brought my pedal back to full working order .

[davepedals]

Agreed, I love my sch1,  not gonna touch it!

[Les Turnbull]

Here is the schematic http://www.hobby-hour.com/electronics/s/arion-sch1-chorus.php
The Caps are a good age now so a recap wont hurt .

[Mark Hammer]

Here is the schematic http://www.hobby-hour.com/electronics/s/arion-sch1-chorus.php
The Caps are a good age now so a recap wont hurt .

I wouldn't be so quick to recommend that.
First, there is a difference between 40 year-old caps made in the 1960's, and compact 40 year-old caps of roughly half the physical size (or even less), made in the 1980's.  My sense is that the more tightly-packed recent ones are less amenable to drying out and being off-spec than their predecessors.  perhaps more importantly, by virtue of being far more compact, they are packed into smaller spaces on PCBs, increasing the risk to the board and components should one go about aggressively removing them.  Keep in mind that the traces and pads for a late 1960's Superfuzz are a whole lot fatter than those for a mid-80's chorus.

That's not to say that a cap couldn't possibly become bad.  But the sort of wholesale replacement of any and all electros is not bound to be an automatic improvement with out any risk.

[bolsonero]

I´ve benn recaping each one and nothing happened.
Mark: The reason of the true bypassing modd is because the buffer does the pedal sound with less bass and way less sag with distortion pedals. I love to use short cables and only three tb pedals so the sound is full and fat. I dislike the buffers, but recognize that never used a fet or high quality transistor to improve the buffer signal. Maybe the shielded cable is a right option but where must I solder the ground?
Many thanks to all the comments and helps!!!

[Mark Hammer]

My own experience is that most pedals will provide more bandwidth than you really need, at both ends.  So the bass rolloff of any buffers is going to be well below the range of the guitar, and the treble rolloff will generally be high enough that a person has to turn their treble below max on the amplifier.

If the input impedance of the buffer could be a little higher and preserve more of the signal, that would be good.  But that can be solved by leaving the pedal as it is, and placing a buffer at the front of your pedalboard, that always stays on.  This will give a low-impedance load to each of your pedal after it, such that their input impedance will be high enough to "keep" all of the signal.

[Les Turnbull]

A trick I have seen on DIY pedals is to ground the effect input during Bypass , could this be done with the Arion chorus .
http://1.bp.blogspot.com/-k5Sh68yVU18/TzGRFKbiALI/AAAAAAAAAlk/CbfaaduUjYQ/s1600/%21Offboard+wiring.png

[Mark Hammer]

Not really, since the unaffected "bypass" is simply the buffered, emphasized-then-deemphasized-and-buffered output, minus the delay signal.

This is one of those instances, perhaps, where the smart thing to do is to simply make or buy a loop-selector, and bypass the entire pedal circuitry externally.  Given how in-demand the Arion chorus pedals are, too, it's useful to leave as much of the internal intact as possible.  Not that everything should be thought of entirely on the basis of resale value, but one should at least have the choice of resale available.

[bolsonero]

Well, unfortunately I put the pedal in original way, with all the transistors and connections like before modding but the clock noise persist.
The good news is that because this problem I am now using my line 6 M9 and be happy with it...   

I will not lose the hopes that will someday solve it.

Or I'll end up throwing it in the trash!

Mark:
I couldn´t found a Jfet transistor. In my town (very little city) there isn´t a radio shack that sell that transistor. In what kind of product can I found a Jfet, a tv or radio or fax for example?

Thanks again!
Regards.