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Old 29th May 2007, 10:45 PM   #11
anatech is offline anatech  Canada
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Hi Sandy,
I know what you mean.

I was being sincere in my previous comments. I'm glad you mentioned the other forum.

Cheers!
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Old 30th May 2007, 10:05 AM   #12
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Default Nurturing Intelligent Audio Design

Forums such as this and Rock Grotto assist participants from diverse backgrounds and interests in exploring fresh audio territory. It benefits all if we can keep open minds!

Having supported democracy, I also feel there are sobering caveats in the field of audio, something akin to ground rules, that must underpin any fruitful discussion. These include my opening salvo regarding the sheer insanity of considering MP3 devices and PC sound cards as premium audio sources.

With >30 years in music - composing, performing, recording, engineering, broadcasting, reviewing; in audio - retail and installation; in computer hardware and digital multimedia; in cable design and assembly - I remain eager to listen and learn. My next challenge is to develop a proper grasp of thermionic and SS circuit design, ultimately to complete my own projects from scratch rather than just modify.

My trusty ears tell me that with 16-bit red book CD digititis (very few exceptions) recorded music standards have actually regressed in the last 25 years. Yes folks, analogue remains the reference point if you intend to seriously and realistically assess audio equipment! SACD had a chance of establishing itself until the industry ineptly undermined it. Now they're onto Blu Ray already and planning for the next stage of wanton, sped-up obsolescence. Innit marvellous?

Anyway life goes on. BTW thanks for the pointer on the "flavour of the month" op-amps, Sandy. Read a whole heap on-line. This coming week promises intense auditioning. New phono stage is scheduled to arrive Wednesday. There'll be slightly more current drained in my house than normal.....

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Old 30th May 2007, 10:58 AM   #13
sandyK is offline sandyK  Australia
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Nightcap.
I think that the reason for the virtual extinction of SACDs
and DVD-A (I own some of each) is due to the general public not giving a damn about quality, just as long as they can hear their favourite music wherever they are. This has been made possible for them by formats like MP3, and the fact that manufacturers are allowed to label any shiny toy as HI-Fi ,without having to qualify their claims.
Interestingly, a better source of music tracks is often present in deluxe edition CD releases, in the form of "the making of"
bonus DVDs. The content is often 48KHZ LPCM, or 5.1 Dolby Digital. As an example the deluxe version of "Norah Jones-Not Too Late" CD has a few music videos, as well as the earlier live performances,with LPCM audio. The live performances have much better dynamic range and sound quality approaching that of SACD/DVD-A.
Currently, their are quite a few 48KHZ LPCM "promo" music videos posted on the Internet. It is a damn shame that the CD audio isn't usually up to the standard of the music companies promo videos. Incidentally, some of these LPCM promos can sound very good indeed, if bit depth is increased to 24bits with appropiate software . Providing of course, that the playback chain is good enough. I use a Music Fidelity X-DAC V3 which upsamples to 24bit 192KHZ for playing this material via SPDIF .
It pays to replace the switchmode bridge rectifier diodes in the typical player's switchmode PSU with UF4007, or , better still
(in my opinion) the even faster, slow recovery type BYV26C. Some judicious placement of sound deadening material in the player, such as self adhesive felt, will also improve the audio quality via SPDIF.
Video quality usually improves too, even via HDMI !
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Old 30th May 2007, 01:43 PM   #14
anatech is offline anatech  Canada
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Hi Guys,
Quote:
I think that the reason for the virtual extinction of SACDs
and DVD-A (I own some of each) is due to the general public not giving a damn about quality, just as long as they can hear their favourite music wherever they are.
This topic is also based in the general publics refusal to constantly replace their libraries of a new media type. They don't seem to mind replacing a worn out LP though.

Add to this that they've been told time and time again that their old 70's equipment is junk (okay, the speakers weren't up to today's standards) then on to last years gear being superseded by the new shiny thing. The new shiny things are not really repairable and spares are generally not in stock. Can you blame them for giving up? The music software and music hardware industries got too greedy and the public turned on them.

I don't think rectifier changes are the proper way to fix a poor power supply design. We've made a big circle of preferred devices and really, the original 400x series work very well. The problem seems to stem from both board layout, toriod transformers and filter capacitors that are too large. That and the use of three terminal regulators that have poor high frequency rejection. With little consideration given to the power supply, there are noise problems throughout the device.

Listening tests and part swapping have some value, but generally go wrong unless they are preceded by some bench time and a little technical expertise. Everyone wants to believe that they are improving the product. I never judge my own stuff until they have been listened to by some brutally honest friends. Children are great here. Wives too sometimes.


-Chris
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Old 30th May 2007, 03:18 PM   #15
jcx is offline jcx  United States
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and of course the only valid way to proceed with mods is to own at least 2 of the device so you have the unmodded device in front of you to switch A/B, level matched, same source material/test signal - not a hrs or days old "memory" of the unmodded sound - people are really poor in the long term sonic memory department
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Old 30th May 2007, 04:29 PM   #16
anatech is offline anatech  Canada
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Hi jcx,
Quote:
and of course the only valid way to proceed with mods is to own at least 2 of the device so you have the unmodded device in front of you to switch A/B, level matched, same source material/test signal - not a hrs or days old "memory" of the unmodded sound
That's how I do it. The mod also has to pass the bench before I'll let anyone listen to it.

Quote:
people are really poor in the long term sonic memory department
Anyone who I've ever seen modify equipment also judges it themselves, you can not judge your own work. Trust me on this!

-Chris
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Old 30th May 2007, 08:43 PM   #17
sandyK is offline sandyK  Australia
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Chris and jcx
I didn't want to go there about greedy record companies and the release of mainly back catalogue stuff. I did manage to get a couple of new releases in both new formats before the record companies gave up on mainstream releases. I agree 100% on the issue of linear power supplies. In fact, I use a little known PSU add-on design by John Linsley Hood to dramatically reduce the output impedance of the power supplies out to >100KHZ. This add-on also greatly reduces noise level, results in a far more neutral sound, as well as increasing channel separation. I was referring to the increasing use of switchmode power supplies in CD/DVD players. These types of modifications are well documented elsewhere.
Are many members of this forum aware that ill informed politicians are legislating to make the use of "intelligent "
switch mode PSUs MANDATORY ? Yes, linear PSUs will be illegal !
Regarding listening tests, 3 of us discuss our mods before implementation and listen to the results as a group. We also use a compilation CD specifically for this purpose , in conjunction with other high resolution material. We are also able to audition unmodified equipment againt modified equipment. This includes Silicon Chip magazine designed amplifiers and preamplifiers, in original and modified states. We also have 2 Oppo DV981HD players (check out their capabilities. They also have an undocumented feature that allows digital volume control via SPDIF, if O/P is set to LPCM) available for comparison, as well as 2 Pioneer DVD-A/SACD players.One of us also owns a Marantz SA11 DVD player.Speakers used include an old Ohm Walshe (Dalek) fitted with plasma tweeters, DCM QED and Infinity speakers fitted with very recent high quality Raven tweeters.
SandyK
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Old 30th May 2007, 09:00 PM   #18
anatech is offline anatech  Canada
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Hi Sandy,
My comments are directed towards the average group of tweakers. Those who do not follow any kind of scientific or documented process. You should see the volume of destroyed equipment in North America!

Over here an idiot with a soldering iron is called a plumber by some. No shortage of plumbers.

-Chris
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Old 30th May 2007, 09:15 PM   #19
sandyK is offline sandyK  Australia
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Chris
I should have mentioned that we have between the 3 of us,
3 x MF X-DAC V3 and a V2. So we have been able to do comparisons all along the way. As a result, 2 of the VB3s are modified as I mentioned in the email. The 3rd is not currently using the 8066, but is using an outboard dual regulated PSU plus OPA2134s internally. Yesterday I replaced the generic front channel IC in a SoundBlaster X-FI card with an OPA2134 with excellent results. I baulked , however at the posted suggestion (elsewhere) of shoving in the highest capacity, most expensive filter capacitor you can find, in place of the existing main filter capacitor. I did however fit a parallel 100nF poly capacitor.
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Old 31st May 2007, 03:18 AM   #20
anatech is offline anatech  Canada
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Hi Sandy,
Quote:
Yesterday I replaced the generic front channel IC in a SoundBlaster X-FI card with an OPA2134 with excellent results.
Odd you should have mentioned this. I have the OPA2134 and the X-FI music (good card). I am about to do the exact same thing that you have. I haven't read anything on the subject at all.

Since I am intending to use this card as a piece of test equipment, I wanted to be cautious. Loop back tests will be run before and after. Did you try this also? I was also going to use small shunt caps and I'm trying to figure out a metal shell for the card to cut down on external noise from the computer. I have two cards.

-Chris
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