WTB: the best passive preamp there is.

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Telstar

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Re: WTB: the best passive preamp there is.
« Reply #60 on: 22 Dec 2008, 10:58 pm »
Any update on the Myth?

Anubisgrau, I also have a F3, but I'm building my own DAC (or a part of it) and I can adapt the output stage to match with a preamp.
What I'm looking for is a fine remoted volume control. Looks like I have found one :)

richidoo

Re: WTB: the best passive preamp there is.
« Reply #61 on: 23 Dec 2008, 02:13 am »
Silonex is the premium brand of LDRs for audio according to the Lightspeed thread. Silonex has some application notes to make a diy VC.
http://www1.silonex.com/audiohm/levelcontrol.html

Note the feedback and LEDs in series (in Fig 15) to assure matched current to each. This is easier than hand matching the LDRs to use voltage input as with Lightspeed.

Their website nav is flakey now, so here is the sitemap to learn more.
http://www1.silonex.com/sitemap.html

Me too wondering about the Myth  :hyper:

Telstar

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Re: WTB: the best passive preamp there is.
« Reply #62 on: 23 Dec 2008, 02:38 pm »
Silonex is the premium brand of LDRs for audio according to the Lightspeed thread. Silonex has some application notes to make a diy VC.
http://www1.silonex.com/audiohm/levelcontrol.html

Note the feedback and LEDs in series (in Fig 15) to assure matched current to each. This is easier than hand matching the LDRs to use voltage input as with Lightspeed.

Their website nav is flakey now, so here is the sitemap to learn more.
http://www1.silonex.com/sitemap.html

Me too wondering about the Myth  :hyper:

Hello,

I just emailed George over diyhifi to get some news :)

Silonex website is horrible to navigate i agree, which optocouplers are to use?
http://www1.silonex.com/audiohm/index.html

The lightspeed thread is too long (but i'll read it all during the holidays)

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #63 on: 8 Nov 2009, 04:29 am »
If there are any AC users from the UK, there will be a Myth LDR preamp for a demo tour there soon. If interested in, pls PM me with your sending details.

No plans for the States, sorry.

Old Mercer

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Re: WTB: the best passive preamp there is.
« Reply #64 on: 17 Jan 2010, 10:08 pm »
If there are any AC users from the UK, there will be a Myth LDR preamp for a demo tour there soon. If interested in, pls PM me with your sending details.

No plans for the States, sorry.

I'm in the UK, and the Myth preamp has been in my system for the past few weeks.  I’m very impressed with the full and detailed sound.   I’m shortly going to have to send it back to the manufacturers’ representative, so I’ve now ordered one for myself and sold my transformer volume control which was also very detailed but sounded thinner and less appealing (possibly, I’ve been advised, as a result of an impedance mis-match with my power amps). 

I don’t know how the Myth compares with the “lightspeed” preamps from Georgehifi or the Eva from DIYParadise    They are more minimalist and that may possibly be an advantage, but I want the convenience of five inputs and I could not use the Georgehifi version with my power amps because their input impedance is no more than 10kohms.   The buffer in the Myth helps provide a very low output impedance that makes it more widely compatible.

jtwrace

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Re: WTB: the best passive preamp there is.
« Reply #65 on: 17 Jan 2010, 10:25 pm »
The buffer in the Myth helps provide a very low output impedance that makes it more widely compatible.

If you like the buffer idea, what about one of these?  http://doddaudio.com/BatteryPoweredTubeBufferPreamp.aspx


thread on AC:
http://www.audiocircle.com/index.php?topic=75028.0

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #66 on: 18 Jan 2010, 11:15 am »
I'm in the UK, and the Myth preamp has been in my system for the past few weeks.  I’m very impressed with the full and detailed sound.   I’m shortly going to have to send it back to the manufacturers’ representative, so I’ve now ordered one for myself and sold my transformer volume control which was also very detailed but sounded thinner and less appealing (possibly, I’ve been advised, as a result of an impedance mis-match with my power amps). 

I don’t know how the Myth compares with the “lightspeed” preamps from Georgehifi or the Eva from DIYParadise    They are more minimalist and that may possibly be an advantage, but I want the convenience of five inputs and I could not use the Georgehifi version with my power amps because their input impedance is no more than 10kohms.   The buffer in the Myth helps provide a very low output impedance that makes it more widely compatible.

glad to see there's someone else apart from me who has a good opinion of the myth attenuator. after a long period of experimenting with almost every passive i could get hold of (with the exception of swiss audio consulting), my final choice are two: myth and tap-x. i've sold every other preamp i owned (more than 10 since 2005). i may be biased towards myth because i know the manufacturers in person but there's plenty of other people here who tried to build a LDR volume control following different threads on DIY forums and they are not really comparable with myth - neither soundwise nor in terms of easiness to use.

especially with the latest version of myth which has no internal wiring - i've got mine upgraded to it (free of charge, kudos to the manufacturer) and the improvement is really, really big. if you by chance have an older version, try to get them back to myth to change the old boards for non-wired ones, it's worth a hassle.

pardales

Re: WTB: the best passive preamp there is.
« Reply #67 on: 18 Jan 2010, 12:44 pm »
Another perspective/offering on the type of PRE being discussed in this thread; its a longish thread and the details trickle out, but there is enough on the first page to explain the basic design which uses LED's and LDR:

http://www.audiophiletalk.com/cgi-bin/yabb2/YaBB.pl?num=1254751267

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #68 on: 18 Jan 2010, 01:20 pm »
Another perspective/offering on the type of PRE being discussed in this thread; its a longish thread and the details trickle out, but there is enough on the first page to explain the basic design which uses LED's and LDR:

http://www.audiophiletalk.com/cgi-bin/yabb2/YaBB.pl?num=1254751267


interesting, so after "myth" we now have "truth" as a bufferred LDR pre. what's the next bombastic name:)?

doug s.

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Re: WTB: the best passive preamp there is.
« Reply #69 on: 18 Jan 2010, 02:02 pm »
here's one thread which indicates a reason one may rather choose any other brand besides myth:

http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-290.html

doug s.

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #70 on: 18 Jan 2010, 02:25 pm »
here's one thread which indicates a reason one may rather choose any other brand besides myth:

http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-290.html

doug s.


frankly speaking i'm a bit fed up of different manufacturers with commercial interests who are using DIY forums to promote themselves and than jumps on whoever is interfering with their own business. seen so many times - and now DIYaudio.com is increasingly a platform for that. making clones and selling them behind the counter. there's always a scapegoat - as tim rawson was in the case with the pass clones - while many other members are just making the same and selling around (at least for me tim rawson was a honest guy who did that openly without hugging nelson pass on DIYaudio and selling his clones behind his back).

george hifi has a similar problem with many users and i understand his frustration. however he's now pretending to be a keeper of a holy optocouplers grail which unfortunately for him isn't the case. he even can't register it as his patent and now he's just jealous of whoever makes a better product based on LDRs. optocouplers should be seen in the very same light as transformers or autoformers. there's no patent on their use as a volume control and anyone can use them - sowther, S&B, promitheus, audio consulting, dave slagle blah blah.

lightspeed mk2 can hold no comparison against myth on any ground. neither in sonics nor in ergonomics. myth is serious, professionally made device whose only common relation with other LDR attenuators is that it actually uses LDRs. the way they are driven and the way the LDRs sonic outputs are matched to a very high tollerance is totally unique concept and george could do much better favour to himself and to DIY community to follow up the myth's lead - there's so many clever solutions implemented in that device.

instead of that, his crew from DIYaudio is completely overlooking a serious instability of the LDRs that produces many troubles - high distortion, channel imbalance, impedance drifting. this can be all solved but you need to change the way how you control and drive LDRs. that's what myth is doing while george doesn't even want to see the mistake. look at the latest post - the guy whose living directly relies on implementing LDRs in the way george is doing it (his LDR matcher) - claims it's a fun to have a different sound on different level of attenuations and it's fun to have 20k  on L and 25k on R channel LDR impedance. what the hell are they talking about,  is that an audio kindergarten?

rollo

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Re: WTB: the best passive preamp there is.
« Reply #71 on: 18 Jan 2010, 02:32 pm »
I have had my fair share of Passives as well. S&B, Promithius, ASL. The S&B was the king IMO until Mapleshade modded the Promitheus. A total rebuild of the trannies and grounding scheme. The results are a much improved sound. My active still leads the pack.
   I have an interest in the Lightspeed to hear if finally a passive has the body, weight and dynamics of the active linestage. If it does with the benifit of the clarity a passive provides I'm in like Flynn.
  For $450, less than have of the Myth it seems like a true bargin. Now if I could only use the Lightspeed internally in my active that might be the ticket.


charles

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #72 on: 18 Jan 2010, 02:41 pm »
Now if I could only use the Lightspeed internally in my active that might be the ticket.

that's not a problem - seen a few DIYed tube amps using LDR attenuators, some were preamps and some were poweramps with a basic LDS passive volume control . very smart solution as the plain LDR attenuation circuit is very cheap, under $50.

even some big names are doing it, i've read on DIYaudio forum that payl hynes has a tube preamp with LDR attenuation in his production.

as to the issue of drive and weight, i replaced my music first copper with myth with massive improvement particularly in this area. however i really like dave slagle autoformers - they certainly have less drive than the bufferred myth but his AVCs can sound smoother and more "polished" (not everyone's cup of tea but sometimes i like that) and i like to have that option in my room. so as i said before, my choice are myth and bent tap-x. music first copper, promitheus, earlier bent TVCs, placette etc - that's clearly behind. in my room and in my system (tubes and horns).

Big Red Machine

Re: WTB: the best passive preamp there is.
« Reply #73 on: 18 Jan 2010, 03:00 pm »
Has anyone used just a volume control like this one?  Sure, no multiple inputs, but can it get it done?  Putting something like this in a nice veneered box could be a cool solution if it mimics the Endler Attenuators in performance (or exceeds!).

http://www.khozmo.com/index.html

rollo

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Re: WTB: the best passive preamp there is.
« Reply #74 on: 18 Jan 2010, 03:07 pm »
that's not a problem - seen a few DIYed tube amps using LDR attenuators, some were preamps and some were poweramps with a basic LDS passive volume control . very smart solution as the plain LDR attenuation circuit is very cheap, under $50.

even some big names are doing it, i've read on DIYaudio forum that payl hynes has a tube preamp with LDR attenuation in his production.

as to the issue of drive and weight, i replaced my music first copper with myth with massive improvement particularly in this area. however i really like dave slagle autoformers - they certainly have less drive than the bufferred myth but his AVCs can sound smoother and more "polished" (not everyone's cup of tea but sometimes i like that) and i like to have that option in my room. so as i said before, my choice are myth and bent tap-x. music first copper, promitheus, earlier bent TVCs, placette etc - that's clearly behind. in my room and in my system (tubes and horns).

 Hey man long time no talk. You and I have had a lot of experience with passives going back to the Promitheus threads. I value and trust your opinion about passives. time for more research on my end . If you say the Myth has more of a full sound I'm interested. Thanks.


charles

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #75 on: 18 Jan 2010, 03:15 pm »
Hey man long time no talk. You and I have had a lot of experience with passives going back to the Promitheus threads. I value and trust your opinion about passives. time for more research on my end . If you say the Myth has more of a full sound I'm interested. Thanks.
charles

hi rollo :D

frankly i've never been impressed with promitheus that much. mine was also plagued with a really bad QC so i sold it very fast. soundwise it was a level bellow anything with S&B 102 transformers such as bent of music first. however given the price, it was a decent sounding product and quite important as an entry point to the wonderful world of passive attenuators.

a bufferred LDR, no matter if myth or anything else (like from the link above), addresses a number of TVC issues. it has slam and drive thanks to the buffers which provides super low ouput impedance (i watched how they measured my preamp - the output impedance was virtually unmeasurable as the entry step at that device was 3 ohm - this was bellow it). maybe an external tube buffer that nick chua provides the same, i don't know - i gave up on his products after that disappointing experience.

still, what i really miss with either LDR or AVC is a ground-lift option that TVC has. that's soooo cool.

Danny Richie

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Re: WTB: the best passive preamp there is.
« Reply #76 on: 18 Jan 2010, 04:06 pm »
Quote
If you like the buffer idea, what about one of these?  http://doddaudio.com/BatteryPoweredTubeBufferPreamp.aspx

thread on AC:
http://www.audiocircle.com/index.php?topic=75028.0

I have heard a lot of passives and nothing so far has been close to that one.

Niteshade

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Re: WTB: the best passive preamp there is.
« Reply #77 on: 18 Jan 2010, 04:13 pm »
Something else to think about:

A good passive that does not use any active or reactive components: They're inexpensive and in no way shape or form can introduce noise into a music system. On top of that, they can be made so that the input impedance stays relatively constant.

anubisgrau

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Re: WTB: the best passive preamp there is.
« Reply #78 on: 18 Jan 2010, 04:25 pm »
i agree - but very often a benefit you gain from transparency and lack of noise with passive attenuators is lost with even the slightest mistakes in how the impedances of your system are matched. this is the problem of all audio problems. what kind of magic you need to implement when assembling the system to make sure that your digital source has 50ohms, your phono RIAA has around that too, and your next source - say home theater - has the same, if you are feeding a power amp of a usual low impedance. i am aware that puristic approach - all passive paths, no buffers - is theoretically better; the trouble is that if your system is a multi-source one, there's no way you can ensure all your sources are doing the same. i came to this solution while using 2.8k DAC which fed via music first TVC into a 10k zout first watt F3 amp made the crappiest bass and loss of drive i could imagine. when i swithced only to a 50k zout tube amps, things changed completely and the impedance mismatch was much less evident, the bass got tight and deep and controlled (with 1.6w SET!!!). than i switched back to a F3 with 10k zout and replaced TVC for myth with (say) 3 ohm buffers - and i've suddently heard am absolutely controlled tectonic bass and lots of energy and slam in lower registers. and when i change a 2.8k zout DAC for altmann attraction which is i think around 100 ohm only, there's hardly a difference in this matter between a TVC and a bufferred LDR VC. go figure.   

Dracule1

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Buffered LDR volume attenuator called Myth
« Reply #79 on: 7 May 2010, 11:08 pm »
Just wanted to revive this thread because this attenuator caught my interest.  Was this buffered passive pre ever produced?