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Posted: Tue 12/25/07 4:35 pm
by tarzanalog
Clips?... yes, please.

Posted: Tue 12/25/07 5:14 pm
by Greenback
A great pice of work.
whould be proud to have one myself.

Posted: Wed 12/26/07 5:30 pm
by rjgtr
Good work. Glad you got it all together. I'm very partial to KT-66s when they are driven. I run KT-66s biased a little hotter because I heard they sound a little better that way, and I have to agree. You might try it.

Posted: Fri 01/04/08 2:00 pm
by morcey2
Just a quick note. The amp made it's public debut last night at the blues jam. It ended up being the house amp for most of the jam. :D :D :D :D It was too loud to really crank it (pretty small theater), but after everyone else left we dimed it (ok, maybe $0.08-ed it) for about an hour and a half. I didn't play for more than 2 or 3 minutes, but the other guys were there swapping it between guitars and cabinets. We had my cabs (2x12 greenback closed back, 2x12 g12h30/V30 open), a matchless with what I think is an OEM version of a g12h30, and a 1960 w/ G12-65(I think). My Plexi6v6 was in the mix too and it was a blast! Glad I brought earplugs.

I was hoping that the recording equipment would be there, but it wasn't so I didn't get any clips. I hope to get some recorded to post this weekend.

Again, Thanks everyone

Matt

Posted: Tue 05/27/08 12:03 pm
by morcey2
Finally some clips!!! These are from the amp show a couple of weeks ago. I didn't do any of the playing which I, and everyone who listens, should be thankful for.

The speaker cab is a sealed 2x12 w/ Greenback reissues. An SM57 mic is about half way between the dust cap and edge. Also, 2 condenser mics were near the back of the theater to pick up some of the natural reverb, and the 3 signals were time-matched and mixed.

Posted: Tue 05/27/08 12:05 pm
by morcey2
More Clips

Posted: Tue 05/27/08 12:07 pm
by morcey2
Last clip.

I would again like to thank everyone who donated parts to this amp and to the Mark Durham fundraiser. I will eventually post pictures also. The amp is currently housed in a Mojo small box head, nothing exciting but it isn't in one of the redneck looking cabs that I have put some of my other amps in.

Again, thanks

Matt

Posted: Tue 05/27/08 12:32 pm
by Alexo
Sounds great, Matt! I'm finally building myself a '45 for my birthday in July and that "Wind Cries Mary" clip has gotten me all excited about it again. Was the amp running KT66's or EL34's?

Posted: Tue 05/27/08 12:47 pm
by morcey2
Alexo wrote:Sounds great, Matt! I'm finally building myself a '45 for my birthday in July and that "Wind Cries Mary" clip has gotten me all excited about it again. Was the amp running KT66's or EL34's?
Should have posted that. It's running VA KT66's and the OT is set to 6.6k. The preamp tubes are a tungsram, a sylvania, and an I65 philips. I don't remember which one is in what position. The KT66's are biased at just under 80%. At 70%, they were a little brittle, but warmed up nicely as they warmed up.

It's an awesome sounding amp. I've already had some serious offers on it, but it isn't for sale. I kept telling one guy it wasn't for sale and his price kept going up. 8) I'll probably be building him a Plexi6V6 in the next month though.

Matt

Posted: Tue 05/27/08 1:34 pm
by LarryLarry
First, thanks morcey2 for posting the clips.

Second - now I'm very confused about how a JTM45 "should" sound.

Questions:

1. Does that amp have a master volume?
2. How/why are you getting so much distortion?
3. What is the difference between the 'clean' and 'dirty' sounds in terms of the amp's settings? (no pedals, right?)

I am the 7th winner of the Mark Durham Memorial Giveaway having also won a JTM45 head and cabinet. My amp is almost Twin Reverb clean until it's almost wide open - and that my friends is loud! The only thing I've done was put in a bias pot. I've run 6V6s, 6L6s and KT66s and they are all basically clean sounding. Yeah, the 6V6s aren't as loud, but still pretty clean.

Now you're gonna make me post sound samples, huh?

Posted: Tue 05/27/08 1:56 pm
by morcey2
LarryLarry wrote:First, thanks morcey2 for posting the clips.

Second - now I'm very confused about how a JTM45 "should" sound.

Questions:

1. Does that amp have a master volume?
2. How/why are you getting so much distortion?
3. What is the difference between the 'clean' and 'dirty' sounds in terms of the amp's settings? (no pedals, right?)

I am the 7th winner of the Mark Durham Memorial Giveaway having also won a JTM45 head and cabinet. My amp is almost Twin Reverb clean until it's almost wide open - and that my friends is loud! The only thing I've done was put in a bias pot. I've run 6V6s, 6L6s and KT66s and they are all basically clean sounding. Yeah, the 6V6s aren't as loud, but still pretty clean.

Now you're gonna make me post sound samples, huh?
Larry,
To answer your first question, I have no idea how a JTM45 is supposed to sound, just this one.

For the rest of the questions:

1. No, no master volume.

2. There are 3 reasons I think we're getting so much distortion. First, 6.6k OT winding breaks up earlier than the 8K usually used on JTM45's. Second, This one has less NFB than it should because I only have it configured for 8-ohm speakers, but has the same feedback resistor value. The original used the 16 ohm winding resulting in more feedback. The last piece I think is the speakers. Third, the greenbacks break up nicely with this and add to the distortion.

3. The difference between the 'clean' and 'dirty' setting was just where the volumes were set on the amp. I think both were on 2 for the clean and the bright on 4/normal on 6 or 7 for the dirty. There were no pedals involved.

I like the bright higher than that to brighten up the distortion, but something shifted in the last month or so and if the bright is turned up above 4, I get oscillation. I've got to track that down now.


and, Yes, You need to post some clips of your JTM! That's one sweet looking amp.

Matt

Posted: Tue 05/27/08 2:48 pm
by LarryLarry
Excellent info Matt, thank you!

I will record some clips this week on the JTM45. I do have 1 greenback so I'll have to use that for some of them. I agree, the greenback's do break down quicker. Currently I have a Celestion Vintage 30 and a '68 Jensen C12N in the 2x12 cabinet I won. They are each very efficent speakers. Gee, maybe that's why it's so loud!

Posted: Mon 07/27/09 12:11 am
by allynmey
RIP Mark....3 years! :cry:

Posted: Mon 07/27/09 9:04 am
by NitroLiq
R.I.P. Mark...you are sorely missed.

Posted: Mon 07/27/09 2:59 pm
by ur12
Wow.....Where has the time gone. RIP Mark

Posted: Mon 07/27/09 3:27 pm
by WaZaK
I never knew the guy: gone before my time here.
But from the comments I read, I guess I wish I had.

Never known, but not forgotten.

Regards to all.

Posted: Mon 07/27/09 5:10 pm
by zaphod_phil
What a sad and tragic day that was.

Does anyone know how his wife and family are doing these days, BTW? The case of that murdered couple in Florida the other week, who had adopted all those disabled kids, reminded me of Mark when I saw it on the news.

Posted: Thu 07/30/09 6:39 pm
by morcey2
I got this amp back for a couple of days because I think the rectifier died. There's just something about a cranked JTM45 that's hard to beat. There's just something to it.

I know why Mark liked them so much. They're both marshalls, but a very different vibe from an 18-watt.

I was really lucky to get drawn for this amp and it's been able to help me with some bills with everything we're going through at the moment.

Matt

Re: 5th winner of Mark Durham Memorial Giveaway

Posted: Wed 01/20/21 8:57 pm
by morcey2
I usually make it a point to not resurrect 12-year-old threads, but I had to share the news. The Mark Durham Memorial JTM45 is back home. I had sold it to a very good friend of mine who has taken care of it for the last 12 years. I needed money for medical bills when I sold it originally. He needed money for tuition for one of his kids so I bought it back. He'll have plenty of visitation with it if he needs it for recording or a gig.

I haven't fired it up yet, but that will probably happen tomorrow.

Matt