JTM-45 Problem with High Treble channel and Speaker Output

[koffo]

Hi all,

This is my first post on this forum.
I just finished a Metroamp JTM 45 build, and after solving the "classical" standby switch squeal I'm facing two new issues now:
1) the normal channel sounds AWESOME but the high treble sounds thin, with a lot of background hum and most of all, the channels seems to be "mixed". If I'm connected to the normal, if I raise the volume of the HT one the sound get brighter as if the two channels are jumpered... Is it normal?
2) only one of the speakers output jack works (the one that is far from the impedance switch). The jacks seems go be connected correctly...faulty jack?

Apart from that, the sound of this amplifier is incredible, also the overdrive when cranked up was a surprise to me!

Thanks in advance for your help, this forum rocks!
Andrea

[Elad E]

I think you should upload some pics of the turret board, inputs, pots and the impedance switch/speaker outputs area.

[koffo]

Hi,

I solved both issues a couple of minutes ago.
The mixed channels were caused by a bad solder on the v1 tube. The stripped yellow sire was properly soldered on one pin but not on the other one.
Same issue for the speaker jack, one of the contacts was loose, and I had to solder it again.
Now everything works, I have no experience on vintage amps, my first amp was a JCM 800 combo, but this jtm 45 blows all the amps I had so far away, clean sound is unbelievable, and the amp is also a good platform for distortion pedals.
Anyway, also if the problems are solved, I'm going to post some pictures of my amp, it is not as gorgeois as many I saw in this forum, but it is my first build and I'm quite satisfied!

Thanks for your help,
Andrea

[Elad E]

great!
I just finished an hour and a half of jamming with mine and I could't agree more - it seems to excel in everything I throw at it - clean, mild overdrive, funky rhythm picking etc.
you may know this already but the schtick, IMO, is running whatever input volume you're using on 9-10 and controlling the volume with your guitar's volume knob. frankly - it completely changed how I use my pedals. I wasn't impressed with my Wampler Tweed '57 and Black '65 before I ran the volumes high - they sound completely different now. I really thought these pedals were either too subtle or sounding nothing like their demos, now the Tweed '57 gets the most play time - I just can't believe how good it is - it can do anything between ZZ Top, Neil Young, the tweed Chicago blues thing and a great Dumble style overdrive. not bad for a pedal I was considering putting up for sale just a few months ago