Need Help To Install A Metro Zero Loss Tone Fx Loop Into A Marshall 2205
- Thread starter mxr2000
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ampmadscientist
Well-Known Member
Recommend you ask this in the Metro amp forum?
Jethro Rocker
Well-Known Member
It isnt a Marshall product but it is for Marshall amps. Works for me.
http://gofile.me/3reJI/fHlNh4v3j
This is for the loop.
I might get one put in my 4010.
http://gofile.me/3reJI/fHlNh4v3j
This is for the loop.
I might get one put in my 4010.
You email George @ Metro...he will email you the instructions "for the loop" and a default amp. (He used a DropBox link before that was changed and some site links just don't work.) I just emailed him a couple days ago...he sent me the needed PDF. But, if you can't interpret how to adapt it...take it to a tech that can. You're doing a high voltage, current limited feed to this particular loop and cannot afford to make a mistake with it.
The instructions that Steve wrote are very easy to follow. Only place where you need to measure and adjust is the dropping resistor to get the correct voltages to the loop. They are excellent and in my opinion completely transparent. I did not install switch in last one - it is on all the time
Yeppers! Yes, I'm debating the switch install for the client...haven't used the Metro build before.
mxr2000
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Hi there my pc can't connect with the link you gave me. what i need to see it?
Jethro Rocker
Well-Known Member
Huh. I used that link before. Go figure. I even read tgrough the instructions. Sorry about that
DeathAdder
Active Member
Do you think this kit would work in a Fender Blues Junior III? When I emailed them they were unclear. I thought they were techs over there and wanted to sell products. The email I got was uneventful, to say the least.
I did some math and the BJ can handle the current of an extra tube, if I need to go that route. But solid state is fine as long as I knew it would work.
I installed one (v3) in my 2203 clone a couple of years ago but it seems that they make this loop kit (and everything else) based around Marshalls.
I mean, electronics is electronics, correct?
I have an effects loop I picked up made by Marshall that was pulled from a reissue (another thread) but I don't know enough about it.
Please help me come up with a solution as my client wants a FX loop in the BJ III I am customizing for him.
BTW, Jethro Tull is one of my favorite bands. I saw them too many times to count. It's a shame they lost Martin Barre but I read Ian wrote most of his parts anyway.
And I miss Barrymore Barlow!!! That was some band (John Evans!!!!!!).
Thanks, Dave
Dave, they're likely expecting you to know those answers if you're going to attempt to do the install. Still, the board should work...will it fit? Well, you'll have to do the homework on that.
The Metro board is pulling off the high voltage supply. Given how low the BJiii supply voltage is, I'd likely pull if from C25 (should be the first B+ cap, 329VDC thereabouts). That's mapped out in detail in the instructions.
Next, since you have a reverb circuit, I'd probably try breaking the audio between the treble pot wiper and R15 (10K) and connect the board's IN/OUT at those points. That way you capitalize on the reverb circuit still parked afterward. If you do that, try parking a 500K to 1M resistor to V2-B's pin 7 to ground to provide the grid leak bias you're breaking when the pots are removed from the circuit by breaking R15. I'd also park a 0.1uF cap between the metro board output and R15. That will ensure that grid leak is satisfied without the Metro board significantly loading the grid leak process (the coupling cap will remove the DC resistive element the Metro board's output may present).
The metro board doesn't come with a schematic...just "detailed instructions". You don't "have" to install the bypass switch, but I did. Two reasons...1 - makes for easy calibration in comparison to the true bypass you get. 2 - easy to check calibration and confirm it's transparency in the circuit. Which I thought it was VERY transparent myself. Not to mention (but I will), I didn't have to make a single adjustment...period!
Follow all the rules they provide...shielded wire dressed as mentioned...they give you some good stuff to work with.
Overall, I do wish the instruction were a bit more detailed with schematic, but over all? It's a really nice board. Be aware...the vertical cap on the metro board and the width of it will make you carefully calculate exactly "where" to park it....and then it has to pass that "noise location" test when done.
Also...I'm assuming that THIS is the schematic of the amp you're referencing...if not, my component references may mean nothing in regard to accuracy.
http://www.thetubestore.com/lib/the...r/Fender-Blues-Junior-III-Schematic-Rev-D.pdf
Good luck!
Brad
The Metro board is pulling off the high voltage supply. Given how low the BJiii supply voltage is, I'd likely pull if from C25 (should be the first B+ cap, 329VDC thereabouts). That's mapped out in detail in the instructions.
Next, since you have a reverb circuit, I'd probably try breaking the audio between the treble pot wiper and R15 (10K) and connect the board's IN/OUT at those points. That way you capitalize on the reverb circuit still parked afterward. If you do that, try parking a 500K to 1M resistor to V2-B's pin 7 to ground to provide the grid leak bias you're breaking when the pots are removed from the circuit by breaking R15. I'd also park a 0.1uF cap between the metro board output and R15. That will ensure that grid leak is satisfied without the Metro board significantly loading the grid leak process (the coupling cap will remove the DC resistive element the Metro board's output may present).
The metro board doesn't come with a schematic...just "detailed instructions". You don't "have" to install the bypass switch, but I did. Two reasons...1 - makes for easy calibration in comparison to the true bypass you get. 2 - easy to check calibration and confirm it's transparency in the circuit. Which I thought it was VERY transparent myself. Not to mention (but I will), I didn't have to make a single adjustment...period!
Follow all the rules they provide...shielded wire dressed as mentioned...they give you some good stuff to work with.
Overall, I do wish the instruction were a bit more detailed with schematic, but over all? It's a really nice board. Be aware...the vertical cap on the metro board and the width of it will make you carefully calculate exactly "where" to park it....and then it has to pass that "noise location" test when done.
Also...I'm assuming that THIS is the schematic of the amp you're referencing...if not, my component references may mean nothing in regard to accuracy.
http://www.thetubestore.com/lib/the...r/Fender-Blues-Junior-III-Schematic-Rev-D.pdf
Good luck!
Brad
mickeydg5
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The loop has been discussed here as well as installed by members like New Religion. Maybe some of them will comment.
Try a search.
Try a search.
DeathAdder
Active Member
Brad,
I am not new to building amps. My first was a SLO 100 followed by a 2203 w/ Metro FX Loop, then another SLO 100. You would think a beginner should start off slow, right? BUt I do have an extensive background in electronics so learning a few rules and some theory and I was off to the races.
I am in the middle of building my dream amp - a Hiwatt DR103. This amp separates the boys from the men, that's for sure.
I know this [post] has probably been mentioned before, probably around the world, but I appreciate your time to answer my question. When you have a unit on your bench you need answers fast.
A search would not have given me the detailed answer you provided.
As I posted on another thread, I have in hand a FX board that was a pull out from a 1959SLP. Another member helped me identify it but I hesitate to use it in favor of a sure thing. I am even considering the Mojo loop and I have already gotten an email back from them.
The Blues Junior is a good amp but it needs so much as far as optimizing it that the late Bill M. (from Blim Audio) dedicated a whole website for this amp. I learned a few tricks but I feel this amp, and many 'CBS era' amps leave a lot to be desired. The trannys put out just what they need to and some of the components are just cheap. What do expect for a $500 amp, right?
Thanks again so much for your input as it saved me a lot of trouble. I still don't know what direction I will go but I have to get this amp off my bench.
I'll keep you (interested) guys informed. -Dave
DeathAdder
Active Member
No members turn up in a search for New Religion, sorry. Maybe he is the ghost living inside your closet.
mickeydg5
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DeathAdder
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I'm just busting your chops my man. A good way to meet people, ya think?
Thanks for pointing me in the right direction, I really appreciate it. -Dave
mickeydg5
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Its all good fun. 
DeathAdder
Active Member
Yea, it turns out New Religion is really NewReligion! Now THAT'S funny! 
