MV upgrade to JP2C

[pkdawg]

I love my V and don't have a JP2C on my radar in my foreseeable future. I'm sure it's great, but for my current needs I like the versatility of the V.

I'm just wondering, for those that find the JP2C has an edge on sound, feel
and response couldn't there be a mod that could be done rather than buying a whole new amp?!?

Just asking for conversation sake and not even looking for a mod. Thoughts?

 

[APEMAN]

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[bandit2013]

+1, Mark IV had it, seemed to have more depth and compression than the V. Do not recall seeing a drive control on the Mark III, perhaps it was on the back as it was a long since I have sold it..

Want to get your Mark V close it not the same as the JP-2C in tone (really works in CH3 which takes the thin out, at least with mine it did) and no mods to the amp required....Throw in a Grid slammer or the Flux drive on the front end. Gets the preamp some juice for more Mojo. Either of those works great in front of the JP as well. I am not much of a fan for such pedals but it really sounds great with a Mark Series amp.

 

[bandit2013]

One last comment, I have played though a new Mark V when I was trying out the TC-50. IMHO on the Mark V, it sounded great, actually much better than the one I own. That got me thinking if I sell what I have I could always get another later. However, since I have the JP-2C that basically has ended my quest for tone especially in the Mark series arena. I would definitely recommend the grid slammer though as it really enhances the character of the Mark V such that I can run both amps simultaneously and not be able to tell the difference with a few exceptions. The notable differences between the two in relation to the power supply and the simul-class vs class A/B power tube section seems to dictate where the sag becomes dominant (seems to be early with the Mark V and late on the JP). The Mark V has more features and tone shaping than does the JP-2C at least on the control surfaces. I can almost dial in all of the voices of the Mark V with the JP-2C just by tweaking a few parameters and settings on the GEQ (where the huge difference is between the two amps, the MKV is mild in GEQ response relative to the JP-2C. If it is the same circuit not sure why there seems to be a difference).

 

[HwyStar]

Very interesting reads Bandit!

 

[APEMAN]

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[bandit2013]

I have not opened up my JP-2C to look inside yet as I have found no reason to remove the chassis. Preamp tube access is from the front by removal of the face plate. No idea what the transistors are that are used in the GEQ. Circuitry must be different though as the FX send is instrument level on the JP and not line level as it is with the Mark V, so I would assume the buffer is different in design. The GEQ also is very responsive with the JP as the cut and boost seems to be more aggressive compared to the V. Perhaps this is just a perceived difference but I really like the GEQ on the JP far more than the Mark V or the 5bandEQ pedal as I have that as well for use with my amps that do not have it.

As to preamp tubes, there is some merit in change in preamp tubes in the Mark V. So far this is the only amp that I own that changes favorably to different preamp tubes.

 

[bandit2013]

I figured I would post a mod here since the OP wants an upgrade to JP2C... While the grid slammer will do the trick or the flux drive will get you there. There is a lower cost solution. Not exactly a mod per say but change on two components of the amp....

Here is the low cost deal to get your Mark V to sound almost identical to the JP-2C. What you will notice that the IIC mode will sound great, Mark IV mode will match the JP-2C CH2 almost to the T, and Extreme mode will be as awesome as the CH3 on the JP. In short, My V was brittle and bright, too bright such that I could not use CH3 unless the treble was either all the way off or below 10am. Presence had to be reduced considerably and bass had to be dialed out in order to retain some note definition when the gain was driven higher. Now with the Mod (requires only your two hands for tools) I love the Mark V and can barely tell the difference between the two and I have both.

Cost out of pocket is less than $40.00. What you need is this: Mesa SPAX7 for V1 ($22.00), Jan/Phillips 12AT7WC ($15.95). I did it this evening and compared the JP-2C to the Mark V though the Vertical 2x12 cab. Before, I did not like the Mark V using V30 speakers as it got brittle the louder the volume got. Now it just sings like the JP. You may even forgo the SPAX7. The key is with V4. Note that it does not seem to affect the reverb. CH1 and CH2 will remain unchanged unless you use the SPAX7 you may notice a slight improvement.

Since I had the tubes already, APEMAN suggested a Mod using the 12AT7 in V6, I thought V5 or V4 would suffice. Finally changed out the tubes and I could not believe how close the Mark V CH3 sounds to the JP-2C. No more need to dial out the bass. The lower gain tube in the driver section of the ladder gain stage for CH3 shifts the midrange hump a bit lower. The tone is incredible. Note: theJP-2C has two pulls on each high gain channel so you only get to the JP tone with the pull switches pushed in (Gain and Presence). 5BEQ also seems to have more affect with CH3. Definitely worth trying if you want the JP-2C tone from your Mark V.

http://forum.grailtone.com/viewtopic.php?f=33&t=73352