New amp build finally started. JTM45 with KT66.

ivan H said:
I like to jumper the channels when playing my Strat or tele through 4 holers, Les Paul or SG go straight into Hi bright channel.
The headcabs offered by Valvestorm are made by guitar cabinets direct & are excellent repro's.
If your interested in one send me a message & I'll let you know the headcab type & options to select on their site for an exact replica of the original smallbox JTM45 headcab. Cheers
Edit:
I tried to link the guitar cabinets direct site/page but couldn't get the link to work. They do cost a tiny bit less than the similar Mojotone headcab. Cheers
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Jumpering the inputs on a four hole head has always been my favorite way to set it up. After I get a bit more accustomed to the amp is doing, I'll start jumping the inputs.

I couldn't find anything on Valvestorm's website about head cabs, but did look up Guitar Cabinets Direct.

https://guitarcabinetsdirect.com/cabinets/marshall-small-box-head-18-watt/
 
SG John said:
Jumpering the inputs on a four hole head has always been my favorite way to set it up. After I get a bit more accustomed to the amp is doing, I'll start jumping the inputs.

I couldn't find anything on Valvestorm's website about head cabs, but did look up Guitar Cabinets Direct.

https://guitarcabinetsdirect.com/cabinets/marshall-small-box-head-18-watt/
Click to expand...
The Valvestorm site doesn't have the headcab's listed on their "products" page, just on the home page with a "contact us" notation for ordering purposes.

That is the cab you want for a JTM45/JTM50/JMP50. The "options" need to be properly selected for a "true" replica. I'll PM the correct options to you. Cheers
 
syscokid said:
Could those secret "options" be ordered directly through Guitar Cabinets Direct?
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Yes, it's all there in the options offered, you just need to select the right ones. It's mainly tolex & trim really.
If you look through the tolex options, there is only two listed as "Marshall" type black tolex. As the "elephant" type wasn't used until a good bit later, it has to be the "other" type Marshall black tolex (light weight black) that needs to be selected.
The handle is a gold British (Hiwatt) type.
Insert piping is small gold.
Baffle Piping is medium gold.
Not sure on the feet as I usually get these from Valvestorm (though I could measure to compare to those in the options).
As the flat lower front cutout lip is already encorporated in this headcab, nothing needs to be selected in this regards (does with Mojotone & others), same with the rear gold mesh. Cheers
 
syscokid said:
New cab looks great! What do you got in mind for the logo?
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Was thinking of either going with the silver and red early style block logos that are going on ebay, or shooting a pm to Cadorman to see how he did his. That way I can make it with my name instead.



Or.... a friend just sent me this. Someone he knows makes them on his 3d printer. Would be funny for about ten minutes, then I'd probably swap it.


Masshole logo.jpg
 
SG John said:
Was thinking of either going with the silver and red early style block logos that are going on ebay, or shooting a pm to Cadorman to see how he did his. That way I can make it with my name instead.



Or.... a friend just sent me this. Someone he knows makes them on his 3d printer. Would be funny for about ten minutes, then I'd probably swap it.


View attachment 54291
Click to expand...
That is legendary!!
 
Looks great SG John. Either the early silver/red or later gold/black type block logo would look great on that.
Modulus Amplification in the UK make up custom faceplates &/or block logos (to your design), really nice quality. I have one of their JMP plexi faceplates ready for an upcoming build, nice thick plexi material, deeply reverse Lazer engraved, much nicer than some of the plexi faceplates available. Cheers
 
Sorry for the necro-post, but I didn't want to start a new one.

Since I bought the DST15 from Bob Detorre in July, he's been asking when I would bring this amp over to his shop for him to critique.

Today, our schedules finally meshed, and I brought it over this morning.

First, he loved the badge I made for it with my name on the amp. When he removed the chassis from the box, he loved how all my component placement and wiring was very orderly, and correct. He also noticed I went the extra distance with the high grade pots (thanks Steve!) Once he was done looking over stuff, he pugged it into the oscilloscope. What he wanted to see was spot-on. The balance between the power tubes was almost identical. As he played with the knobs on the amp and scope, he kept complimenting my attention to detail and making a very nice amp. He played it a bunch afterwards. As he was playing it, he loved how quite it was, and there was no hum. Even with LED lighting in his cellar. He said he tried going to LED to not have the hum of fluorescent lights. He said that they're just as bad, but the cellar is brighter. Then, we swapped the Gold Lion KT66 tubes for a set of 1950s Genelex (GEC) KT66s that I had bought when I was building the amp. We didn't even have to mess with the bias. The wave on the scope was almost perfectly balanced, as well as the readings on the meter being really tight as he increased volume. Looking forward to playing this the next time we jam.

My ears have been saying this a great amp since it was finished. Especially with all the help Steve, Ivan, and Chris gave me when I was building it. It was nice to hear Bob's input. Especially since I just can't send the amp off to Alaska or Australia for some input. It was a fun time, as Bob let out his local humor and complained that he now has competition only a couple of blocks away. He also called me a bastard for finding a set of 1950s KT66s that don't have loose parts inside of it. He is also bugging me to start another build. Maybe after I get back from training in Germany mid November. Got to see what I have, and what I need for a build first.

Sorry that I have no photos. Maybe I'll add something tomorrow.
 
SG John said:
Sorry for the necro-post, but I didn't want to start a new one.

Since I bought the DST15 from Bob Detorre in July, he's been asking when I would bring this amp over to his shop for him to critique.

Today, our schedules finally meshed, and I brought it over this morning.

First, he loved the badge I made for it with my name on the amp. When he removed the chassis from the box, he loved how all my component placement and wiring was very orderly, and correct. He also noticed I went the extra distance with the high grade pots (thanks Steve!) Once he was done looking over stuff, he pugged it into the oscilloscope. What he wanted to see was spot-on. The balance between the power tubes was almost identical. As he played with the knobs on the amp and scope, he kept complimenting my attention to detail and making a very nice amp. He played it a bunch afterwards. As he was playing it, he loved how quite it was, and there was no hum. Even with LED lighting in his cellar. He said he tried going to LED to not have the hum of fluorescent lights. He said that they're just as bad, but the cellar is brighter. Then, we swapped the Gold Lion KT66 tubes for a set of 1950s Genelex (GEC) KT66s that I had bought when I was building the amp. We didn't even have to mess with the bias. The wave on the scope was almost perfectly balanced, as well as the readings on the meter being really tight as he increased volume. Looking forward to playing this the next time we jam.

My ears have been saying this a great amp since it was finished. Especially with all the help Steve, Ivan, and Chris gave me when I was building it. It was nice to hear Bob's input. Especially since I just can't send the amp off to Alaska or Australia for some input. It was a fun time, as Bob let out his local humor and complained that he now has competition only a couple of blocks away. He also called me a bastard for finding a set of 1950s KT66s that don't have loose parts inside of it. He is also bugging me to start another build. Maybe after I get back from training in Germany mid November. Got to see what I have, and what I need for a build first.

Sorry that I have no photos. Maybe I'll add something tomorrow.
Click to expand...
The "hum of florescent lights"
is really caused by the filament wire layout inside the amp.

To get rid of the buzzing noise, the filament wires need to change position.
But this is a really common problem in all early Marshall amplifiers.

2. There needs to be an HT fuse, to protect your output transformer.
I recommend you add that.
 
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