Merlin's Practical Serial Effects Loop layout

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Turret
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Re: Merlin's Practical Serial Effects Loop layout

Post by Turret »

norburybrook wrote:Excellent. I've just put a metro zero loss Fx loop in my JTM45 and it works great but there's something not quite right about seeing PCB's and IC's in a point to point hand wired guitar amp.
IC? Like op-amp? Can you take a picture of that?
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xtian
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Re: Merlin's Practical Serial Effects Loop layout

Post by xtian »

@arcturus: The loop gets it B+ from the same node as V1a. No additional filtering needed.

@norburybrook: You're right about the master volume. The whole reason for the loop in this amp was that I like to play at home with low volume and a lot of preamp gain. The loop is perfect for reverb in this situation.
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vibratoking
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Re: Merlin's Practical Serial Effects Loop layout

Post by vibratoking »

Excellent. I've just put a metro zero loss Fx loop in my JTM45 and it works great but there's something not quite right about seeing PCB's and IC's in a point to point hand wired guitar amp.
Don't let your eyes and your bias determine what should be in there. PCBs are every bit as good or better when done properly. Tubes generate harmonics differently than silicon, but you're not looking to generate anything with the loop. You are just looking to preserve the tone.

xtian - glad to hear your report about the loop. Another tool in the box is always a good thing.
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dorrisant
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Re: Merlin's Practical Serial Effects Loop layout

Post by dorrisant »

Good to hear you got it working... I've been looking at that circuit for a while. Thanks for pushing the way!

Tony
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Gaz
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Re: Merlin's Practical Serial Effects Loop layout

Post by Gaz »

Since this thread's been necrobumped, Xitan, what prompted you to bypass the both cathodes in this circuit?
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xtian
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Re: Merlin's Practical Serial Effects Loop layout

Post by xtian »

Gaz wrote:Since this thread's been necrobumped, Xitan, what prompted you to bypass the both cathodes in this circuit?
I did not. I followed Merlin's schematic. Notice that the input cathode, pin 8 in my drawing, is not bypassed. That 10u cap does NOT go to ground, it goes to the Send volume control.
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Gaz
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Re: Merlin's Practical Serial Effects Loop layout

Post by Gaz »

Ah, yes, I missed that. But you did bypass the recovery stage, correct? I'm asking because I built this circuit and had too much recovery gain with the 2k2 UNbypassed recovery stage. I had to use a split plate load to get it back to unity. Not sure if that was the best way to do it... Merlin?
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norburybrook
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Re: Merlin's Practical Serial Effects Loop layout

Post by norburybrook »

vibratoking wrote:
Excellent. I've just put a metro zero loss Fx loop in my JTM45 and it works great but there's something not quite right about seeing PCB's and IC's in a point to point hand wired guitar amp.
Don't let your eyes and your bias determine what should be in there. PCBs are every bit as good or better when done properly. Tubes generate harmonics differently than silicon, but you're not looking to generate anything with the loop. You are just looking to preserve the tone.

xtian - glad to hear your report about the loop. Another tool in the box is always a good thing.

very true. The whole point of the metro loop was to have 'zero loss' and as transparent a loop as possible. they've certainly achieved that.

here's picture.


Marcus
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ampdoc1
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Just another Loop

Post by ampdoc1 »

I used this loop (which was shown as a Dumble circuit on this site in the mid 2000s.) Love it,...plenty of gain, and it works great as a master vol also.
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Gaz
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Re: Just another Loop

Post by Gaz »

ampdoc1 wrote:I used this loop (which was shown as a Dumble circuit on this site in the mid 2000s.) Love it,...plenty of gain, and it works great as a master vol also.
Sure you're talking about the same one? This one is from the second version of Merlin's book, not the AC coupled CF as seen in the Dumbleator.
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angelodp
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what amp

Post by angelodp »

Xtian, what amp is this loop in? Would this work for both PP and SE
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xtian
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Re: Merlin's Practical Serial Effects Loop layout

Post by xtian »

Please see post #5 in this thread. On the schematic I show that it goes between tone stack and PI. no reason it won't work in a SE.
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angelodp
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yes

Post by angelodp »

Yes, I see that but just wondering what amp you implemented this into.

Ange
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xtian
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Re: Merlin's Practical Serial Effects Loop layout

Post by xtian »

Marshall 1987
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angelodp
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nice

Post by angelodp »

Bet thats a great sounding amp. Do you peter this method to the Dlator variety of loop? Can you draw any comparisons.
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