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#366
yoshi
Participant

Hello DD:

I have been fully updating my Pristine 2 this past year.

1. Bypassed the tweeter pot with a 50 watt , 4R metal fin resistor( Mills 4R, MRC50 50 or 75 watt). Very cheap cost for a significant upgrade in HF presentation. $5.00 each…

2. Factory installed Toroid 1: the Toroid 2 will not fit in your backlplate housing, and you may even have to put a spacer piece of wood to raise our the backplate housing up to accommodate the greater depth of the Toroid 1 transformer. I did with 3/4” thick strip.

3. Replaced the bias supply module with the new regulated supply. This was installed my me. Roger will provide you all the parts, new bias control pot and wiring schematic. The new module will not fit in flat, so you must cut of one of the flanges ends and mount it on end for it to fit. 2 way tape, hot glue and a new small door hinge on the existing mounting screw works perfect to securely get it in. Has at least 30% more bias capability, and is voltage regulated.

4. New bass-focused panels, mounted in the current pristine 2 frame. The pristines have 60 degree dispersion angle and you will need to provide Roger with the exact width of panels to have them specially made, due the wider panel than the current 545.
They can be installed by you at home. The new panels take some time to break in, but are quite an upgrade, particularly the bass area. However, the original panel worked great for me for over 20 years. I had to turn up the old bias supply almost 100% to reach a full bias on the new bass focused panels. The new bass focused panels have a wider spacing of the grid wires, which Roger says enhances low frequency production. Consequently, I have found that the old bias modules a little under capacity for the bass focused panels.

5. Clean the 3 banana plugs form the backplate to the panels and check the tension on the plugs for secure fit.

6. I also had a panel arching repair before I purchased new bass focused panels. A repair is home doable if you have an issue there, with a degree of difficult and a lot of time. The Mylar is extremely delicate. If you have to wade into the panel for investigation, do not touch the mylar or even hard blow on it. You will pierce the Mylar with almost no tension on the membrane. I did… they will still work, but you will likely never be satisfied with a pierced panel membrane.

7. If you do not the tip toes for these frames, get them. Big difference on this speaker.

8. sallie home made backwave panels. firm rigid insulation panel,5’ H x 4” ( double up on 2”) thick, just placed behind the frame bas, angled parallel to the panel, centered, will improve acoustics and the front wave launch. I made a a stand with wood base, 2 dowls on the plate for rear support, and 2- 4 ‘ dowls mounted and glued vertical in the base, for panel support. works great and you can’t see them from the listening position.

I would also suggest you figure out why the resistors blew and if there other electrical component issues in there.

Good luck and keep us posted.

Ken