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Post by ChrisB on Oct 9, 2014 19:09:41 GMT
How about something like this? |
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Post by speedysteve on Oct 9, 2014 19:36:33 GMT
I tried a few passives. The stepped resistor ones did not do it for me. They were quite nice ones too.
I had a TVC transformer passive in my system for several years. It was narrowly trumped by the £2400 odd (new) Puresound L10.
I suspect you have to pay lots to get better actives (ones that don't bring stuff to the party that should not really be there).
I never heard the Puresound L30 (beast of a pre) but it has a very good rep, and so it should for the price of £7900 odd price tag.
There are of course the Audio Note ones at £38K and ~£72K I think it is. I did get a chance to hear the £38K one but it could not drive the load (same load that Puresound and TVC drove happily). It just popped - dumping DC it seemed. Put the Puresound back in and all was perfect again...
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Post by MartinT on Oct 10, 2014 5:17:07 GMT
It's a funny thing, but I far prefer silver kit to black.
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Post by Deleted on Oct 25, 2014 13:41:18 GMT
Passive every time for me.
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Post by Clive on Oct 25, 2014 20:10:25 GMT
Get a passive right in terms of impedance and system gain structure....I find TVCs and AVCs are incredibly transparent and play at low volumes very well indeed.
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Post by John on Oct 25, 2014 20:50:44 GMT
Yes the key is getting that right
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Post by Deleted on Oct 26, 2014 1:58:49 GMT
A normal decent quality pot, or better still a stepped attenuator, is all you need in most cases. So long as the driving impedance is 1K or less, the input of the power amp is 10K or more and the pot is between 10 - 30K then all should be fine so long as the power amp is sensitive enough to give the required volume without any further amplification.
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Post by julesd68 on Oct 26, 2014 11:26:43 GMT
The only passive pre I have tried is the Icon Audio - www.iconaudio.com/portfolio-item/passive-passive-pre-amp/I liked the looks and build quality but it lasted about two seconds in my system as the presentation was flat as a pancake in terms of dynamics and drive. Wish I could remember what power amp I was using, might have been my old Quad 405-2. Might have been a mismatch somewhere but wasn't tempted to try another one ... The active pre-amps I had after that were much more satisfying - a battery powered Croft prototype and also an Audio Note M-Zero. Using an integrated now which could be hooked up to a pre. |
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Post by yomanze on Oct 28, 2014 14:00:16 GMT
A normal decent quality pot, or better still a stepped attenuator, is all you need in most cases. So long as the driving impedance is 1K or less, the input of the power amp is 10K or more and the pot is between 10 - 30K then all should be fine so long as the power amp is sensitive enough to give the required volume without any further amplification. In theory this is right, but as an example I had a DAC with an output impedance of 83R, a 20K pot / passive pre into an amp with a 47K input impedance and 0.4V input sensitivity - all optimal for passive operation. However, my active pre has better slam and sounds more "correct" where the passive (an NVA P90SA) was thinner and lacking the balls and oomph of the active with the active losing only a little bit of "transparency", but having a much more 3D, rich and enveloping sound. Having said this the active preamps I've compared are world-class & very expensive in comparison to a passive (Krell KRC-3 and LFD DLS). |
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Post by danielquinn on Oct 28, 2014 14:29:51 GMT
I am currently experimenting with this very issue with my NVA mono blocks . i have built my own single input passive pre amp with a pot the doc gave me . I have a gain issue as the volume will not go high enough .
I could solve this via a new moving coil [ current one is 0.1mv output ] and a new phono amp with impedance setting [both of which i intend to buy eventually]
but before i do i want to experiment with a active pre amp to see for myself . Especially if that pre as a moving coil input as i am therefore eliminating a box
currently looking at audiolab 8000c ist generation or a rotel rc 970bx .
anybody any comments on this particulat method of assessment and/or these products - much appreciated .
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Post by Deleted on Oct 28, 2014 17:08:29 GMT
I can't say I've personally had any issues with using a passive other than in a few cases a lack of gain. Sound quality is great and sounds more open than an active in most cases. YMMV.
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Post by Sovereign on Oct 29, 2014 12:25:59 GMT
Just taken delivery of a Coffee LDR passive pre amp, sent to me from one of the chaps on AoS.
Really looking forward to the comparisons with my Croft Valve Active Pre.
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Post by pre65 on Oct 29, 2014 12:28:34 GMT
Just taken delivery of a Coffee LDR passive pre amp, sent to me from one of the chaps on AoS. Really looking forward to the comparisons with my Croft Valve Active Pre. I had a listen to that some while ago. I'd be interested to hear your opinion.  |
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Post by Sovereign on Oct 29, 2014 12:32:22 GMT
What did you compare it to?
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Post by pre65 on Oct 29, 2014 12:42:06 GMT
What did you compare it to? I have a World Designs Pre 3 and an Audionote copy made by Bluebell Audio. Both are valve designs and transformer coupled to the output. |
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Post by Sovereign on Oct 29, 2014 12:46:02 GMT
What were your comparative thoughts on the Coffee?
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Post by pre65 on Oct 29, 2014 12:51:54 GMT
What were your comparative thoughts on the Coffee? |
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Post by John on Oct 29, 2014 13:00:45 GMT
I be interested if it beats the Croft
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Post by Sovereign on Oct 29, 2014 13:18:43 GMT
Well I had a very quick listen last night. I'll have to give it a proper demo in the next couple of days.
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Post by Sovereign on Oct 29, 2014 22:40:17 GMT
Unexpectantly I have a couple of hours free tonight. So it was straight into the kitchen for a large glass of red, a walk accross a wet patio to my hifi room.
I spent 30 minutes or so listening to my hifi using the LDR pre amp. I have spent this time listening to Christian Mcabe which is heavy and funky double bass led Jazz album, a great artist if anyone is looking. The LDR is very impressive. Better timing, more defined bass, more detail and separation. There you go thats my review, shortest one ever! What would I keep???.........................................at this stage it would be the LDR!
I honestly had a strong bias towards my £2k Croft Valve pre amp, but I cant deny it as much as I want to, the LDR is stupidly good and should'nt beat pedigree of the Croft. I need more time to live with the LDR for a couple of weeks to see if I get on with it long term but I can't see why I wouldn't. Of course this is all in my hifi with my ears etc, My TQ class A amp with the croft is bloody marvellous, but I have thought it may be on the slightly lush side. I think, at this stage, the LDR addresses that. Before the Croft I was using a Glasshouse passive and the Croft brought more weight, size and pressence to the party. The LDR brings all that and more.
This may all be a little premature as its onlt been anhour and a half. And I know you can mod the Croft as Marco has with a better PSU, then again the LDR is running off a wall wart and I'm sure the chaps on DIY Audio can mod the crap out of it. Watch this space.....
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