Can someone help me?
I came across this zx450, and BAM all WIMA caps.
Are there anymore of these? As all research shows these amps with the cheaper dark brown round edged caps...
Is this a special amp? I've owned 4 others and looked high and low and don't see any others like this...
Any input?
zx450 with all WIMA caps
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speedsmith
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zx450 with all WIMA caps
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Hmm... must have been a custom job by a previous owner. Usually they look like this.
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speedsmith
- Posts: 12
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Advantage being??stipud wrote:Check your crossover card IC's for a Burr-Brown logo of sorts...speedsmith wrote:I'm not that technical unfortunately, how do I check the op amps?
Like this...
Alpine CDA-9887
PG ZX-450 v2
PG ZPA0.5 v2
Polk SR-6500 (active)
(2) PG 10" RSDC-104 (sealed)
PG PLD-1
PG 1/0, 2 Farad cap
Dynamat Extreme Door/Trunk
(Anybody have a HO alternator for a late model Accord V-6?)
PG ZX-450 v2
PG ZPA0.5 v2
Polk SR-6500 (active)
(2) PG 10" RSDC-104 (sealed)
PG PLD-1
PG 1/0, 2 Farad cap
Dynamat Extreme Door/Trunk
(Anybody have a HO alternator for a late model Accord V-6?)
Provided they are installed within proper tolerances, the Burr-Browns are considered better sounding than the cheaper generic op-amps. Just like people think WIMA branded caps sound better than regular electrolytics.flogger11 wrote:Advantage being??
Changing the opamps to burr-brown in a ZX450 would be quite an expensive operation. The crossover is quite complex and has a large number of chips to replace. Simpler amps like the MS series only have two IIRC.
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CarAudioGuru
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- Joined: Fri Jul 04, 2008 9:03 am
- Location: Phoenix
On the note about modifiying amplifers and supposed sound quality changes:
Actually , back in the day, we tried all kinds of shit to improve the sound of the amplifers. One time we (Dom and I) told engineering (Jeff Payton and Ben Heil) that we could hear the difference in opamps. Of course they broke out the "BullShit" card immediately and said "Prove it"!
Give us your "list " of the 5 coolest opamps and we will modify 5 PLD1's.
So we listed what we currently used JR4560's, then we went to TLO74's, and AD854 (? Hey! it was 17 yrs ago, OK!!) and 2 others. Ranging in price from $ 0.12 cents a piece to $ 4.52 cents a piece. So we set up a listening test with a MS275, our reference THIEL loudspeakers and a Alpine 7909 for source. We didn't look inside the 5 - PLD1's sitting in front of us, but procedded to do our listening tests. After we were done and presented our findings to Enginneering - it turned out that in last place was the JR4560 (the ones we currently used) and the super high buck AD854 was the best. So again, engineering called "BullShit" and said that we looked inside the PLD's and that is how we really determined which was which. We said "No way" we did it honestly!! So they said "OK, assholes -lets see you do it again, and we will remove ALL markings so you can't tell, and change cases even!".
So we did the test again. And again, in EXACT same order we chose the opamps! Blew engineering away (me too!!) So, Dom, being the ever tweak said "What if we tweaked the second choice opamp? Which was a TLO74, and biased it too Class A operation and test it versus the AD854? "
So we did that and the TLO74 beat the AD854. Enginnering then fully modified a MS275 and chageds out ALL JR4560 opamps to the "hot rodded" TLO74's. We did another listening test comparing a stock MS275 to the super modified MS275.
And who won?? Drum roll please!
Dom and I could NOT hear any significant difference! And we wanted to!
BUT...NO cigar!
WE both think that to hear a SIGNIFICANT difference we would have had to change all the caps to WIMA, ALL opamps to the hot rodded TLO74's and done high freq bypass on the large caps. Maybe we could hear a difference. MAYBE? At a cost of about $12.00. Which means it would have cost and additional $60.00 retail. At the time the MS-275 was THE most expensive 75 watt per channel stereo amplifer out there. Making it $60 MORE at retail would have been tough at best.
So changing out all the caps to WIMA "theortically" should sound better. BUT...without full "Blind" listeneing tests, I don't know. I wouldn't bet BIG money on it either (even thou my audiophile inner self wants it to believe, my logical side says TEST it first!)
Just "food for thought" my friends. I agree that there should be sonic advantages to modifiying amplifiers. But if these mods are made and NOT verified by blind listening tests, then I am the one breaking out the BullShit card (which I have printed up and give out at my seminars, still today!!)
Actually , back in the day, we tried all kinds of shit to improve the sound of the amplifers. One time we (Dom and I) told engineering (Jeff Payton and Ben Heil) that we could hear the difference in opamps. Of course they broke out the "BullShit" card immediately and said "Prove it"!
Give us your "list " of the 5 coolest opamps and we will modify 5 PLD1's.
So we listed what we currently used JR4560's, then we went to TLO74's, and AD854 (? Hey! it was 17 yrs ago, OK!!) and 2 others. Ranging in price from $ 0.12 cents a piece to $ 4.52 cents a piece. So we set up a listening test with a MS275, our reference THIEL loudspeakers and a Alpine 7909 for source. We didn't look inside the 5 - PLD1's sitting in front of us, but procedded to do our listening tests. After we were done and presented our findings to Enginneering - it turned out that in last place was the JR4560 (the ones we currently used) and the super high buck AD854 was the best. So again, engineering called "BullShit" and said that we looked inside the PLD's and that is how we really determined which was which. We said "No way" we did it honestly!! So they said "OK, assholes -lets see you do it again, and we will remove ALL markings so you can't tell, and change cases even!".
So we did the test again. And again, in EXACT same order we chose the opamps! Blew engineering away (me too!!) So, Dom, being the ever tweak said "What if we tweaked the second choice opamp? Which was a TLO74, and biased it too Class A operation and test it versus the AD854? "
So we did that and the TLO74 beat the AD854. Enginnering then fully modified a MS275 and chageds out ALL JR4560 opamps to the "hot rodded" TLO74's. We did another listening test comparing a stock MS275 to the super modified MS275.
And who won?? Drum roll please!
Dom and I could NOT hear any significant difference! And we wanted to!
BUT...NO cigar!
WE both think that to hear a SIGNIFICANT difference we would have had to change all the caps to WIMA, ALL opamps to the hot rodded TLO74's and done high freq bypass on the large caps. Maybe we could hear a difference. MAYBE? At a cost of about $12.00. Which means it would have cost and additional $60.00 retail. At the time the MS-275 was THE most expensive 75 watt per channel stereo amplifer out there. Making it $60 MORE at retail would have been tough at best.
So changing out all the caps to WIMA "theortically" should sound better. BUT...without full "Blind" listeneing tests, I don't know. I wouldn't bet BIG money on it either (even thou my audiophile inner self wants it to believe, my logical side says TEST it first!)
Just "food for thought" my friends. I agree that there should be sonic advantages to modifiying amplifiers. But if these mods are made and NOT verified by blind listening tests, then I am the one breaking out the BullShit card (which I have printed up and give out at my seminars, still today!!)
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Larry Frederick
"Original PG Guy"
"Original PG Guy"
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brenzbmr@sb
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wow, its been a while since i been here and
i see larry is posting.
i actually want to print that card, ill never forget that seminar i went to years ago where you actually made a mention of that card.
many alohas to you larry,
thanks for all your help in the past.
when are u coming to the big island.
marc
i see larry is posting.
i actually want to print that card, ill never forget that seminar i went to years ago where you actually made a mention of that card.
many alohas to you larry,
thanks for all your help in the past.
when are u coming to the big island.
marc
You may have subs in your car........but my doors sound better!
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fuzzysnuggleduck
- Soy Milquetoast
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It seems to me that Larry was saying he would have to replace ALL the opamps and caps in the amp to make a difference in SQ, but I suspect since the PLD1 is a much simpler device, all (one?) opamps were replaced in the PLD1 and that's why he could tell the difference.stipud wrote:So you noticed a difference in SQ when upgrading opamps in the PLDs, but not the MS amp? Did you guys ever upgrade the PLD opamps because of your findings, or are they still running JR4560's today? Perhaps this would be a great upgrade for those of us with PLDs!
SOLD: '91 PG 4Runner
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CarAudioGuru
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Fuzzy! Exactly! Good catch.
Yes we all felt that it was because the PLD was such a simple device with few parts that the modifiaction made such a big difference.
As soon as you get into an amp, especailly one with crossovers, phase, gain, etc. Now it is more complicated and we feel that it is more circuit layout and parts implemtation that makes the real difference.
We did then and we still do now.
Audison SRx (new series) LRx and the new Thesis line are all the basic same circuit with better and better parts utilized as you go up the line. As a prime example.
On a different note. I wish someone made the BassCube again.
What a killler product.
IF anyone wants any "BullShit" cards I have THOUSANDS (no BS!)
PM me and I will mail you some
Yes we all felt that it was because the PLD was such a simple device with few parts that the modifiaction made such a big difference.
As soon as you get into an amp, especailly one with crossovers, phase, gain, etc. Now it is more complicated and we feel that it is more circuit layout and parts implemtation that makes the real difference.
We did then and we still do now.
Audison SRx (new series) LRx and the new Thesis line are all the basic same circuit with better and better parts utilized as you go up the line. As a prime example.
On a different note. I wish someone made the BassCube again.
What a killler product.
IF anyone wants any "BullShit" cards I have THOUSANDS (no BS!)
PM me and I will mail you some
Larry Frederick
"Original PG Guy"
"Original PG Guy"
Bringin' this thread back from the recent dead... Oddly enough I found the ZX250 that I have for sale right now has mostly WIMA caps in it. It is one of the earlier ZX250's, so perhaps it was factory done in the early models?
Also, the broken 900.7 I bought has WIMAs throughout as well, and that one was from another member on here, and found to be broken right out of the box, brand new. So, that one for sure was not a mod, unless it was done specially in house.
I will try to remember to take pictures later. I am not sure I buy into the capacitor SQ impact though. I do fully agree that there is such a thing as capacitor distortion, and it is well and scientifically proven, but whether that distortion is audible or not is a whole different debate. A well designed amp, like these, with a rated, scientifically measured THD of less than .02% is already well bellow the accepted human threshold of ability to hear, regardless of which caps they used.
Later,
Jason
Also, the broken 900.7 I bought has WIMAs throughout as well, and that one was from another member on here, and found to be broken right out of the box, brand new. So, that one for sure was not a mod, unless it was done specially in house.
I will try to remember to take pictures later. I am not sure I buy into the capacitor SQ impact though. I do fully agree that there is such a thing as capacitor distortion, and it is well and scientifically proven, but whether that distortion is audible or not is a whole different debate. A well designed amp, like these, with a rated, scientifically measured THD of less than .02% is already well bellow the accepted human threshold of ability to hear, regardless of which caps they used.
Later,
Jason
