Charlie - Is this diagram "official" in the sense that it came from Dahlquist? I've seen a few versions of this diagram over the years.? I have a pair I want to upgrade at some point and want to confirm the source of guidance. I agree with your philosophy on changes - best to stay as close to the original as possible given the engineering a design behind it. I've always felt the DQ-10's design was its greatest feature and its biggest liability. Something about it beckons one to mess with it, to try and improve it. I'm open to "upgrades" but I need to see real data to support the change, otherwise you're just chasing a dream based on somebody else's opinion.
I will add all 5 versions of schematics I have to the Files section.
On Fri, Sep 10, 2021 at 5:04 PM Charlie Conger <
ctconger@...> wrote:
[Edited Message Follows]
The higher voltage caps are fine. Using "high power" coil means heavier wire with lower series resistance. This will slightly increase the level of the drivers that is fed from the respective coil. this could be good or bad thing depending on whether that drivers level is to low or too high relative to the others. In general coil do not go bad, ?I would leave them alone.?
John looks like he had good advice. I will say i have the necessary equipment to thoroughly tested caps and the I have the same yellow caps as yours. they were all fine. However if you are replacing all the caps in the other xover might as well do them all. THE?ClarityCap PX are good choice if within your price range.?
This sheet may help
Dahlquist DQ-10 Modified Schematic.pdf
If the drivers are original they are the more likely suspect in terms of causing audible colorations. Both of my tweeters had odd impedance curves and one was totally dead. The voicecoil lead wire was broken on that one. When i disassembled the driver to repair it I noticed a huge glob of adhesive that had hardened over most of the corrugated tweeter surround. This impeded dome motion. I was able to gently remove most of the adhesive on the inner surround using very small exacto knife. It is like brain surgery so i don't recommend trying this unless you are confident in your skills. Removing the adhesive greatly improved both the tweeter sound and the impedance curves. The midranges also had hardened surrounds which I softened by gently pushing the cones in and out by the surrounds.
I would add if exact replacements were available I would have used them instead. The Renar replacements are out of the my price range if they are all replaced.
My original goal was to restore as close to original. They sounded great restored that way. The project has since changed, I am doing some relatively minor upgrades. Going well so far. ?i leave one speaker as the reference and then compare in mono. Also have made tons of measurements and used those as a compass to guide any changes. All measurements are confirmed by listening. Any time a change is made that is NOT confirmed by both measurements and listening to be better it is undone. As the redesign progresses a larger percentage of the time is spent listening. Right now it is 80% listening.?
?
?
SpongeSound