Will
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Post by Will on Apr 23, 2009 11:48:42 GMT
Posting this as a follow up to the thread here rockgrotto.proboards.com/index.cgi?board=barry&action=display&thread=3631I've been buying parts in for my SC Class A HA, and thought that I would try this stepped attenuator from e-bay, from vintage audio lab. cgi.ebay.co.uk/DACT-Type-23-Stepped-Attenuator-Potentiometer-50K-2a3_W0QQcmdZViewItemQQ_trksidZp4634Q2ec0Q2em14Q2el1262QQhashZitem270375156703QQitemZ270375156703QQptZLHQ5fDefaultDomainQ5f0QQsalenotsupportedI think this is the same one that Canjunkie and cjarchez have bought. Although I've not had a chance to wire it up, I must admit that the 'feel' of this one is much nicer in operation than the one I bought for my Jaycar/SCHA. To put it in very simple (aren't I..) terms, the £17 one I originally bought turns with a "CLUNK, CLUNK, CLUNK", whereas the new one (a whole three English pound more expensive) turns with a smoother "thuk, thuk, thuk" Obviously, this beast can only call itself DACT type, by virtue of it's use of SMD resistors. The rest of the experience is most likely very different. Tx off.
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Deleted
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Post by Deleted on Apr 23, 2009 19:58:30 GMT
Yep! Still haven't installed it though.
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robertkd
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Post by robertkd on Apr 24, 2009 12:21:32 GMT
Posting this as a follow up to the thread here rockgrotto.proboards.com/index.cgi?board=barry&action=display&thread=3631I've been buying parts in for my SC Class A HA, and thought that I would try this stepped attenuator from e-bay, from vintage audio lab. cgi.ebay.co.uk/DACT-Type-23-Stepped-Attenuator-Potentiometer-50K-2a3_W0QQcmdZViewItemQQ_trksidZp4634Q2ec0Q2em14Q2el1262QQhashZitem270375156703QQitemZ270375156703QQptZLHQ5fDefaultDomainQ5f0QQsalenotsupportedI think this is the same one that Canjunkie and cjarchez have bought. Although I've not had a chance to wire it up, I must admit that the 'feel' of this one is much nicer in operation than the one I bought for my Jaycar/SCHA. To put it in very simple (aren't I..) terms, the £17 one I originally bought turns with a "CLUNK, CLUNK, CLUNK", whereas the new one (a whole three English pound more expensive) turns with a smoother "thuk, thuk, thuk" Obviously, this beast can only call itself DACT type, by virtue of it's use of SMD resistors. The rest of the experience is most likely very different. Tx off. Will, they do look interesting, enough so, to order one and see how they really preform mind you I'm under no illusion that this will be fully DACT performance but I'm sure it will be damn good and doubly so for the price. Awaiting delivery Robert
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Will
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Post by Will on Apr 24, 2009 12:31:36 GMT
Odds-on yours will pass a signal earlier than mine does, Robert.
Delivery was quick, mind you. 10 days for Hong Kong to the UK is pretty good.
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Post by Deleted on Apr 24, 2009 21:38:20 GMT
I have now ordered one as well. I will be interested to see how it performs in comparison with the DIYFidelity version, which although a bit clunky in operation, clearly outperforms the Alps Blue Velvet in my SC HA. Alex
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robertkd
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Post by robertkd on Apr 24, 2009 22:13:49 GMT
Alex,
be interesting to hear your comments comparing the two, I'm sure it will stac up fairly well given the Asian attenuators I have tried already.
Robert
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Post by Deleted on Apr 24, 2009 22:37:40 GMT
Robert I may have a high resolution system, but I expect that unless the differences are very pronounced (unlikely) that I will be struggling to give an accurate comparison of them. Someone like Leo, yourself, JeffC or Nick ,may be able to however. I specifically mention Nick, because I was quite impressed at how easily he picked the differences between those supposedly identical files on my HDD without me prompting him. Alex
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leo
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Post by leo on Apr 25, 2009 0:07:10 GMT
When time allows I'd like to get one of these attenuators without the resistors and fit my personal favourite SMD types BTW some SMD resistors can be quite bad sounding, I personally try to stay away from thick film, a lot are noisy and not as tight tol as thin film
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robertkd
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Post by robertkd on Apr 25, 2009 1:06:07 GMT
When time allows I'd like to get one of these attenuators without the resistors and fit my personal favourite SMD types BTW some SMD resistors can be quite bad sounding, I personally try to stay away from thick film, a lot are noisy and not as tight tol as thin film excuse me sir, but wouldn't that be just a switch without the resistors But seriously yes I do understand your reasoning. Robert
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leo
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Post by leo on Apr 25, 2009 11:57:01 GMT
When time allows I'd like to get one of these attenuators without the resistors and fit my personal favourite SMD types BTW some SMD resistors can be quite bad sounding, I personally try to stay away from thick film, a lot are noisy and not as tight tol as thin film excuse me sir, but wouldn't that be just a switch without the resistors But seriously yes I do understand your reasoning. Robert you know what I mean though
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robertkd
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Post by robertkd on May 6, 2009 10:36:34 GMT
Ta Da, ok it's kinda fitted mmm well it's wired in due to a difference in bushing size it is roughly clamped to the panel of the test bed. surprisingly ok, I'm not knocking it I just need more time to listen. That and I have also modded the test bed so that it no longer has the zener diodes now features78L/79L 15's for hte op amp supply as well as removing the ceramic cap and series resistor details as per my last update in SC HA mods these mods have improved resolution a even more. tell what really takes some getting used to is the 300 + degree rotation which puts dial position right out the window, mind you that's simply a relative thing.. One thing I had to carefully resolder one of the resistors in upside down as most of the plating forming the connection had been broken, likely in transit as I also ordered some of their PP capacitors for another project aka speaker cross over. Robert Ok a picture
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Will
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Post by Will on May 6, 2009 11:56:47 GMT
Looks good Robert. I would guess that if you've made other changes at the same time, the change that the attenuator has made will be harder to hear. How have you found the SQ since you removed the dinosaur?
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robertkd
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Post by robertkd on May 6, 2009 12:04:27 GMT
Looks good Robert. I would guess that if you've made other changes at the same time, the change that the attenuator has made will be harder to hear. How have you found the SQ since you removed the dinosaur? oh sure I modded the input and op-amp supply on the weekend and thought that bought better dynamics and clarity, and yes the attenuator I think has added a tad more to the already stacked plate As for Allosaurus well yes a little less rumble at times Robert
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Post by Deleted on May 6, 2009 14:43:13 GMT
But does it have less bite now ;D
Oh, and does your your " 'ello-sore-arse" eat curry?
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robertkd
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Post by robertkd on May 7, 2009 12:38:14 GMT
But does it have less bite now ;D Oh, and does your your " 'ello-sore-arse" eat curry? no but my mega-sore-arse does
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robertkd
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Post by robertkd on May 7, 2009 12:54:13 GMT
Ok an update on the tech-no side well seriously I think this DACT look a like is an improvement. more central sound stage no not in a mono sense but center is well more central, more pinpoint as it where, detail seems better given an already clean and lucid SQ presentation (from the weekends mods) that bit more. Still more listening but I'm impressed with the attenuator (switched resistance ) even over the blue velvet (atm) this ain't a huge difference but as it is I think every bit counts. Will i think you will also be impressed, you know when you need a break form digging foundations and sorting the garage when I say switched resistance the arrangement is a string of resistors between input and ground, the output is simply a tap point in the string of resistors. Robert
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Will
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Post by Will on May 7, 2009 17:53:00 GMT
Thanks for the feedback Robert.
It's good to know that it'll compliment the SC class A (or at least my expectations of it!)
thukthukthuk - nice action. (I must put it away, otherwise I'll break it)
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Will
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Post by Will on May 7, 2009 18:02:16 GMT
Errk! There is a thread over at Head-fi, with people asking about this same attenuator. However, someone has pointed out a link to a real DACT attenuator (CT2 - 50k) for £88!! I really tempted to raid the Buffalo fund, but I have to resist ! Edit: A link would be good, wouldn't it! www.headamp.com/order/index.htm#diyparts
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Will
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Post by Will on May 8, 2009 10:02:02 GMT
Is that 10mm copper pipe on your op-amp, Robert?
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robertkd
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Post by robertkd on May 8, 2009 11:12:24 GMT
Will, no it's some 0.5 mm * 25mm copper rolled on to a drill bit shank then "petalled" as it where Robert
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