Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Colas LeGrippa on March 23, 2024, 11:10:54 pm

Title: JCM 2000 TSL100 issue
Post by: Colas LeGrippa on March 23, 2024, 11:10:54 pm

Hi my friends, I have a JCM2000 triple super lead 100 on my bench. The issue is that the clean channel is humming loud  without a jack inserted in one effect loop ( there are 2 ).  With the male jack inserted, the hum is still.present though.
How could I get rid of this problem permanently ? I opened it up ,  it's jam  packed in there..
The crunch and lead channels are fine.
Thanxx
Colas

Title: Re: JCM 2000 TSL100 issue
Post by: stratomaster on March 23, 2024, 11:55:28 pm

These amps are plagued with problems.  Do yourself a favor and check the revision of the board.  Before a certain revision (Issue 20 is the confirmed good/latest revision) the fiberglass is conductive and leads to problems all over the place, but mostly with respect to bias. 

Title: Re: JCM 2000 TSL100 issue
Post by: sluckey on March 24, 2024, 12:19:13 am

Quote from: Colas LeGrippa on March 23, 2024, 11:10:54 pm

Hi my friends, I have a JCM2000 triple super lead 100 on my bench. The issue is that the clean channel is humming loud  without a jack inserted in one effect loop ( there are 2 ).  With the male jack inserted, the hum is still.present though.
How could I get rid of this problem permanently ? I opened it up ,  it's jam  packed in there..
The crunch and lead channels are fine.
Thanxx
Colas

Cut off the power cord at the chassis.    :l2:

Title: Re: JCM 2000 TSL100 issue
Post by: Latole on March 24, 2024, 04:39:59 am

Why do you work on effect loop. ?

Did you replace tubes with good ones ?

Title: Re: JCM 2000 TSL100 issue
Post by: shooter on March 24, 2024, 05:02:43 am

Quote

The issue is

cold solder
crappy board
bad connectors
crappy jacks
poorly treated workers
lack of quality control


The last one I worked on, I got running, told the owner to SELL IT TODAY 'cuz I ain't working on this amp any more. ( I "fixed it" 3 times!)

Title: Re: JCM 2000 TSL100 issue
Post by: Latole on March 24, 2024, 05:04:20 am

Quote from: shooter on March 24, 2024, 05:02:43 am

Quote

"...... told the owner to SELL IT TODAY 'cuz I ain't working on this amp any more. ( I "fixed it" 3 times!)

Very good advice !

Title: Re: JCM 2000 TSL100 issue
Post by: Colas LeGrippa on March 24, 2024, 07:17:39 am

Sluckey,  as you suggested me I cut the power cord at the chassis...you should have seen the big spark happening !!!! You owe me a pair of side cutters now.... :laugh:


I had in mind these amps were crap, too many controls, in both front and back panels. Opening it up,  I didn't have no surprise. This company sells crappy amps just because of the MARSHALL logo in the front.What would have  thought Jim
Marshal himself about it ?


I must admit though that the tone of the crrunch channel is good. At Marshall, they tried to build a versatile amp with the TSL100, but they sure made an error.  Money is leading the world now.


Thanks for your vomments.


Colas

Title: Re: JCM 2000 TSL100 issue
Post by: Colas LeGrippa on March 24, 2024, 07:25:15 am

....comments, rather.

Title: Re: JCM 2000 TSL100 issue
Post by: Latole on March 24, 2024, 07:38:28 am

The companies give us what we ask for: high-powered amps with a wide range of sonic possibilities at very low cost.
Quality can't be expected