Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Peavey Windsor to JCM800 Conversion.
#11
 I see the only Power Supply mod is the addition of the choke , which your doing, cool.

When I was reco-ing my Aussie vintage amp I got a circuit from the resurrected company for the 100 watt model. Mine is an eighty watt one. It turned out the only diff was a few caps in the power supply.

That power amp mod seems to be mainly to the phase inverter. It might bump up the output a bit.
That might also work your transformers more.

2203's are notoriously loud. There's a mod for them changing the output valves to KT88's.[ Even Louder ]
[-] The following 1 user Likes GoldenVulture's post:
  
Reply
#12
I think you should upgrade transformers only if you are going to change the amount of power they put out. All that BS about transformers making your amp sound better is the same as tonewood.
Do as thou wilt . Aleister Crowley
Reply
#13
Agreed about the transformers. Only change them if your output gets bumped significantly.
Old Hi Fi geeks that existed back in the 50's> 60's , like my uncle, used to run their systems at 16 or 32 ohm on the out puts of their amps. Supposedly the amp delivers a greater frequency range [ bandwidth ] at the higher ohmages. It reduces your power output but makes up for it in increased fidelity. Probably not the realm of guitarists that are actually going for a less clean sound.

The same is true of modern amps. 4 Ohms is louder than 8 Ohms but has a worse frequency response as is 8 Ohm to 16 Ohm.
[-] The following 1 user Likes GoldenVulture's post:
  
Reply
#14
(05-11-2016, 10:19 PM)GoldenVulture Wrote:  I see the only Power Supply mod is the addition of the choke , which your doing, cool.

When I was reco-ing my Aussie vintage amp I got a circuit from the resurrected company for the 100 watt model. Mine is an eighty watt one. It turned out the only diff was a few caps in the power supply.

That power amp mod seems to be mainly to the phase inverter. It might bump up the output a bit.
That might also work your transformers more.

2203's are notoriously loud. There's a mod for them changing the output valves to KT88's.[ Even Louder ]

I definitely believe that choke will make a difference in the feel of the amp. The resistor they use in place of the choke just doesn't feel right. Not the same as the 800's, plexi's, and clones I've played.

There was an output jump after the preamp mod. I was running the MV between 3-4. Now, 2 is knocking shit off the walls. I don't know if loud is going to be the word for it after the rest of the mod. Obnoxious would probably be a better fit. I'm starting to think an attenuator or isolation box would be a wise investment.

I'm also wondering if I can change that MV control to a LOG pot and it make a difference. That sudden jump from nothing to loud is brutal. It needs a slower sweep for the first 25% of the adjustment. Just for the times I can't crank it up to 5-6 on the MV.

There is also an FX loop trick I learned from Krank amps. They used an FX loop level control as a second MV. You set the preamp and MV to taste, then use that FX level control as the real MV. It was a pretty cool trick. Just not sure if it's doable on this type of amp. I'd have to read up on that one.

It could be those WXT+'s making it seem louder as well. I've read that they will do that on most amps. It almost makes me wonder if I can adjust the amp to run 6v6's. I love those tubes in my 50W Stealth.
I hear Mexico is nice this time of year.
Reply
#15
I learned how to tame those Fender Hot Rods with a EQ in the loop,easy and not expensive just has to have a volume slider.
Do as thou wilt . Aleister Crowley
Reply
#16
(05-12-2016, 10:55 AM)Oinkus Wrote: I learned how to tame those Fender Hot Rods with a EQ in the loop,easy and not expensive just has to have a volume slider.

I used to do that with my very first tube amp. It was 4x6l6 Peavey Ranger.

I'm looking into doing a Post Phase inverter MV.
If all my digging and studying is right, I can leave the Pre PI MV in place as well. It would leave me better control of the preamp. The Lar Mar PPIMV is what I'm looking at. It seems to be the best version by a landslide.

This is the best $50 mod box ever. Whatever this amp turns into in the coming weeks, I'll still be under $150 invested in it. Best fucking toy ever!
I hear Mexico is nice this time of year.
[-] The following 2 users Like karpathion's post:
  
Reply
#17
It's so cute! I really thought it would be a little bigger.
Everything else came in a few days ago. 

Once this part of the mod is done, It's pretty much a 2203. It'll have a little more gain, and be a little less squishy than a stock 800, but who complains about that?
I felt 40-50H was a bit much.

[Image: 14b840.jpg]
I hear Mexico is nice this time of year.
[-] The following 1 user Likes karpathion's post:
  
Reply
#18
You can always get less gain by turning it down , you can never get MORE gain when it is maxxed out. Has to be one of the best upgrade deals we have seen.
Do as thou wilt . Aleister Crowley
[-] The following 1 user Likes Oinkus's post:
  
Reply
#19
Where the hell am I supposed to put this thing? The only open spots inside have a transformer in the way on the underside. I'm thinking it needs to be of close the PT, but 2 of the mounting holes will be under the PCBs. Looks like my best option. Any opinions?

[Image: 14c4nv.jpg]

[Image: 14c4pz.jpg]
I hear Mexico is nice this time of year.
Reply
#20
Do you have a top side pic of the chassis ?
Reply


Possibly Related Threads…
Thread Author Replies Views Last Post
  Peavey XXL sounds pretty damn good! karpathion 1 2,659 01-14-2017, 12:22 PM
Last Post: youngthrasher9

Forum Jump:


Users browsing this thread: 1 Guest(s)