al-III 48" ribbon x-overs with poly caps

Custom Equipment Mods.
Post Reply
angelod307
SILVER-7 TUBE AMP
Posts: 2669
Joined: Sat Jun 06, 2009 10:56 pm
Location: manning, sc

al-III 48" ribbon x-overs with poly caps

Post by angelod307 » Wed Oct 06, 2010 2:54 am

nice. real nice. more easy going and effortless. and that is only with several hours play time. not bad for $100 worth of dayton 75uf caps. real nice i tell you.
CarverFest: I just go for the arts and crafts

User avatar
BillD
R.I.P. Friend
R.I.P. Friend
Posts: 7126
Joined: Wed Jun 06, 2007 8:29 pm
Location: The west's most mid-western town, Scottsdale, Arizona

Re: al-III 48" ribbon x-overs with poly caps

Post by BillD » Wed Oct 06, 2010 11:03 am

Glad you like them. I'm bypassing the high pass and low pass filters (that have electrolytics in them) and going with an active crossover. Still need to replace the one 76µF electrolytic cap in the notch filter, and have a pair of polyethylene caps on order.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
_________________
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer

User avatar
mbskeam
(pair of) SILVER-7t's
Posts: 2185
Joined: Mon Jan 25, 2010 2:32 am
Location: Woodinville Wa

Re: al-III 48" ribbon x-overs with poly caps

Post by mbskeam » Wed Oct 06, 2010 5:25 pm

Still need to replace the one 76µF electrolytic cap in the notch filter, and have a pair of polyethylene caps on order.
pics please and a diagram would be nice also...... [-o<
Mbskeam

SILVER 7's
Amazing Line Source
2 SVS PB16 SUBS
#1 BLACK BEAUTY's made by the man, the myth, the legend Bob Carver
CARVER: TFM-75, TFM-45(3), SD/A-490T
SUNFIRE: Tube pre
WTL Amadeus GTA+DV DRT XV-1t
2 sets of ALS'3, set of SILVERS, set of PLATS
AUDIOCONTROL: phase coupled activator
KENWOOD: BASIC M2a (2)

“Youth ages, immaturity is outgrown, ignorance can be educated, and drunkenness sobered, but stupid lasts forever.”
― Aristophanes

The only thing I'll feel......will be the RECOIL
Necronomicon Ex-Mortis....... Klaatu Barada Nikkto
"We should seek the greatest value of our action"

User avatar
BillD
R.I.P. Friend
R.I.P. Friend
Posts: 7126
Joined: Wed Jun 06, 2007 8:29 pm
Location: The west's most mid-western town, Scottsdale, Arizona

Re: al-III 48" ribbon x-overs with poly caps

Post by BillD » Wed Oct 06, 2010 6:22 pm

OK, I did take the time to map the AL-III Plus crossover. First a picture of the original.
P1020719.JPG
P1020719.JPG (230.3 KiB) Viewed 1011 times
Now, mapping the schematic, I came up with this (matching the components labelled on my picture).
AL-III+.jpg
AL-III+.jpg (39.6 KiB) Viewed 1011 times
And, here's how I plan to change the crossover (simply eliminating the high and low pass filters, and replacing C4 with a polyethylene cap). Of course I'll be using an external active crossover. I'm going for a cross someplace between 150Hz and 200Hz.
AL-III Plus.jpg
AL-III Plus.jpg (31.68 KiB) Viewed 1011 times
The cap replacement came in today, so here's a look at the size difference.
P1020720.JPG
P1020720.JPG (207.82 KiB) Viewed 1011 times
I measured the caps, and they are both above 75µF. One is about 75½ and one is about 76½. I'll measure C4 when I get it out of there, but I imagine it will be anywhere from 70 to 85µF. Electrolytics, even the best of them, are seldom close to their rating.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
_________________
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer

User avatar
mbskeam
(pair of) SILVER-7t's
Posts: 2185
Joined: Mon Jan 25, 2010 2:32 am
Location: Woodinville Wa

Re: al-III 48" ribbon x-overs with poly caps

Post by mbskeam » Wed Oct 06, 2010 8:23 pm

thanks.... \:D/ \:D/ \:D/ \:D/ \:D/ \:D/
Mbskeam

SILVER 7's
Amazing Line Source
2 SVS PB16 SUBS
#1 BLACK BEAUTY's made by the man, the myth, the legend Bob Carver
CARVER: TFM-75, TFM-45(3), SD/A-490T
SUNFIRE: Tube pre
WTL Amadeus GTA+DV DRT XV-1t
2 sets of ALS'3, set of SILVERS, set of PLATS
AUDIOCONTROL: phase coupled activator
KENWOOD: BASIC M2a (2)

“Youth ages, immaturity is outgrown, ignorance can be educated, and drunkenness sobered, but stupid lasts forever.”
― Aristophanes

The only thing I'll feel......will be the RECOIL
Necronomicon Ex-Mortis....... Klaatu Barada Nikkto
"We should seek the greatest value of our action"

Post Reply

Return to “!!! MODS !!!”