JM Signature started

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telentubes
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JM Signature started

Post by telentubes »

I have a JM Signature underway. Wanted to use the 50 Watt Schumacher OT I got from Xtian a while back and this seemed like a good fit. The PT is a Magnetic Components 18005. It is oriented 90% from any of the other builds I have done, or the typical layout you see for these amps, but this is the quietest I could come up with so I'll go with this unless you guys know of a reason I shouldn't. I am using the schematic that has been floating around for a while, drawn by Aaron, as well as all the ideas and layouts from a myriad of posts, including the latest from Taylor. Thanks to everyone.
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norburybrook
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Re: JM Signature started

Post by norburybrook »

you've got further than I have with mine :D

Looking good though. I plan on getting mine started 2nd week of March. Just waiting for a few things so I can get my parts order in to Tube Town.

MC
Bombacaototal
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Re: JM Signature started

Post by Bombacaototal »

telentubes wrote: Mon Feb 20, 2017 8:59 pm I have a JM Signature underway. Wanted to use the 50 Watt Schumacher OT I got from Xtian a while back and this seemed like a good fit. The PT is a Magnetic Components 18005. It is oriented 90% from any of the other builds I have done, or the typical layout you see for these amps, but this is the quietest I could come up with so I'll go with this unless you guys know of a reason I shouldn't. I am using the schematic that has been floating around for a while, drawn by Aaron, as well as all the ideas and layouts from a myriad of posts, including the latest from Taylor. Thanks to everyone.
Looking great! On the tonestack did you use the 250ka mid with .05uF? For me that always looked a bit odd configuration. For me it would be either 100kb with.05uF or 250ka with.01uF, so I'm just curious of what you went for
telentubes
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Re: JM Signature started

Post by telentubes »

The schematic has a .047uf and a 250KA pot. Taylor's layout has a .047 with a 100KB pot. Not sure what I'll do yet.
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xtian
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Re: JM Signature started

Post by xtian »

Nice! BTW, that OT is rated as 60-watts, so go get 'em, tiger.
I build and repair tube amps. http://amps.monkeymatic.com
Bombacaototal
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Re: JM Signature started

Post by Bombacaototal »

One thing that I found odd and still haven't managed to come to a conclusion is how John sets ups his amp as far as EQ setting (attached). The mid is way down and the treble is way up, which for me indicates a Skyliner kind of stack, whereby his settings are approximating it to a classic/fender style with the mid dip (scoop)
If he was using this setting with a classic I think it would sound like a really bright amp, which is not the case

Taking into account that Taylor (Classic stack) had access to the official signature model and Aaron was based of a prototype (more like a skyliner) maybe John's amp is not identical to the signature?

But then another confusing fact is that the proto was signed 2009 and the Mayer sig is from 2006
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telentubes
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Re: JM Signature started

Post by telentubes »

60 Watts. Even better! The great tone of your Tamalpais got me motivated to use that OT.
Another inspiration was attending NAMM in Anaheim last month, and getting a chance to play through a bunch of the Two Rock's amp line up. Hard to hear in the din of NAMM, but the Crystal was my favorite. The sales rep told me it is based on the JM. Not sure which version, but what a sweet amp! Tone for days.
Thanks for the comparisons Bombacatotal. I will pour over the schematics some more.
Bombacaototal
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Re: JM Signature started

Post by Bombacaototal »

telentubes wrote: Mon Feb 20, 2017 11:19 pm 60 Watts. Even better! The great tone of your Tamalpais got me motivated to use that OT.
Another inspiration was attending NAMM in Anaheim last month, and getting a chance to play through a bunch of the Two Rock's amp line up. Hard to hear in the din of NAMM, but the Crystal was my favorite. The sales rep told me it is based on the JM. Not sure which version, but what a sweet amp! Tone for days.
Thanks for the comparisons Bombacatotal. I will pour over the schematics some more.
Here some info on crystal and gut shots

http://ampgarage.com/forum/viewtopic.ph ... 4&start=30
telentubes
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Re: JM Signature started

Post by telentubes »

Some progress. Starting to populate the chassis after drilling most of the holes. I'm waiting on the send/return for both the reverb and the effects loop until I can see where they will best fit. It's a Watts chassis that I shortened and "welded" back together with Alumiweld (The PT end is where the weld is. You can see it in pic #2). Milled a piece of curly maple for the face.
Any opinions about preamp tube shields?
JM Chassis.jpg
JM Inside.jpg
JM Front.jpg
JM Tube Shields.jpg
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Last edited by telentubes on Thu Mar 02, 2017 3:11 pm, edited 1 time in total.
Aaron
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Re: JM Signature started

Post by Aaron »

Nice work.
Now the fun begins!
telentubes
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Re: JM Signature started

Post by telentubes »

Made some progress. There's a lot going on with those switches. They took some time.
I'm following the Aaron schematic so my layout is a little different than the posted layouts, and those are the component values I'll start with.
The preamp volume pot is next to the input jack as I thought the wire runs were too long if both volume pots were together on the right side.
The bright switch is ON-OFF-ON, so I have two choices of caps.
Probably won't put in the "effects loop" as I never use them.
JM Sig inside chassis.jpg
JM Sig tone switches.jpg
JM Sig Rectifier.jpg
JM Sig Loop .jpg
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norburybrook
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Re: JM Signature started

Post by norburybrook »

very nice :D gives me something to aim for with mine in regards to quality workmanship :D



Marcus
telentubes
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Re: JM Signature started

Post by telentubes »

Norburybrook, Good to follow your projects at the same time as this one. I also have a 124/102 that I'm messing with so your comments about your 102 are appreciated.
telentubes
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Re: JM Signature started

Post by telentubes »

Still plugging away.
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norburybrook
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Re: JM Signature started

Post by norburybrook »

Nice work :D

I'm still on tour and have projects backed up in the studio so haven't had time to get going on my build. My order from Tube Town came yesterday though so I have everything..I think......why do fender jewel lights NOT come with bulbs???? doh!!! didn't even think about ordering separately........

I'll get started soon.

Marcus
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