My New JMD501 Has A Strange Fizz

[SteveD]

Welcome to the forum Vavoom.

[Vavoom]

Welcome Vavoom, what speakers were you using with the JMD head? I have a few different cabinets and find that the G12H-30s sound great with the 100 watt head, I don't get this fizzyness some of you are getting. The eq is very responsive on the JMD and would just tweak there to remove it.

Hey Surf,
I tried my JMD 100 Head through:
4x12 Marshall Straight Cab with V30's and GT75's (X pattern)
4x12 Marshall Angle Cab with GT75's
1x12 Mesa Cab with a C-90

Same result. However I would like to say that if it IS or NOT digital artifact, it is pretty negligible. I didn't even catch it till the second day. It happens mostly when combining two different note frequencies. Dying off frequencies.....that sort....This is where analog tube technology with it's infinite variable as opposed to the ole on/off--one's and zero's has an edge. Just my opinion.

HOWEVER, if I had some change in my pocket...I just may repurchase a JMD. I miss that darn amp! The sounds it got were pretty amazing.
I played that sucker for 30 days and returned it on the 30th day at the witching hour.

Amps are kinda like cars. You never wanna sell em, but you got to some times....because of this or that....no room, something better, some new flavor.....this tone gives me a boner this month, then another tone is knocking at my door.....ain't it fun though?

Here is my BIGGEST request from Marshall. Most people do NOT play their amps on 10 ALL the time. Install the voltage regulator/attenuator that is on the AFD on ALL or MOST of the tube amps. Maybe even have some defeat switch to take it out of the circuit for the purests. Most attenuators (mine included) do NOT do the amp justice. And I don't have to tell most of the people in this forum....you guys have been there and done that. The VM is a prime example. Just like the Plexi or a 900, the magic doesn't happen until your family is ready to kill you.
Even in some Pub/Club gig situations, they are just too loud. Okay, I'm getting wayyyyyyyyy of topic.

Later,

Bill
Newbury Park, CA

[guitarest]

That will never happen Bill; although some amp do offer a 25/50/100 option. This is exactly why the trend right now is for smaller wattage tube amps like the lil Marshall 5 watts, the 15 watts and many other amp manufacturers. Vox even takes one of theirs down to a 1/4 watt.....

[JC1]

That artifact seems to be a product of having the signal distorted and eqilized "before" being chorused. I'll bet your amp internally is set up that way like my JCM800 with the added parallel FX Loop I added "after" the tone stack. I played around with different things to see if i could get rid of the artifact but nothing worked. That leads me to believe there's nothing wrong going on internally with the circuitry.

Anyway, on another note, I removed the diodes in my 4210 50w combo and installed another preamp tube. I Rearranged them it similiarly to the Soldano slo 100 amp inregards to the OD section. I needed to do a few tweaks to the Soldano circuitry schematic and wow, unbelieveable sustain! Notes sound like warm butter, a sweet tone! Mesa Boogies Rectroverb Over Drive channel is almost identical to Soldano slo 100's, & I have a Rectroverb, but I like the tone of mine better! I'll upload a schematic if I can get it to upload. I've been having some problems getting that to work.

I also cleaned up the Baxandall with some change in values. Now I have a very clean warm channel & a super high gain one with just a sweet, buttery tone. Oh, it has the artifact too on the overdrive. Again, my effects go through a FX Loop after the tone stacks.

Cheers,

JC

-- Mon Mar 07, 2011 3:18 pm --

Can pictures jpg, be added here as attachments? I tried to add some pics from the Marshall Factory from 1983. Can't seem to get them to attach.

[Beck-Ola]

Should be no problem uploading a jpg. Just go down to the "Upload attachment" box below the submit button, browse to find your pic, attach it, and then place it in-line where you want.

[JC1]

I tried that several times. I browse, select the jpg. pic I want to upload, and the box comes up in the left corner saying upload in progress. After the box closes, I see the attachment is added, however, when I submit it, nothing shows up as attached. It worked fine for the schematic I uploaded yesterday, but not with a picture? The pic isn't a large file, but does anyone know what the limit is bit wise on atachments? Maybe that's where the problem is.

-- Thu Mar 10, 2011 10:08 pm --

Welcome to the forum Vavoom.

Hi Steve,

I sent you an email. Did you see it yet?

JC