Vacuum Tube Motherboard?

NRG = mc²

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Sorry, right now I'm on 56k modem, when I get back home in september I can upload the whole 40mb original which is longer and much better (in the audio department too).

Meanwhile, it was captured on a Pentium 150@180 so we couldn't crank the res up too much.
 

NRG = mc²

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The speaker is nothing one can't find at any old concert, but I've never seen someone have them in their living room 8)

Two people have a hard time lifting them. They were dismantled, shipped over from the states in the late 70s and then my friend's father re-built the entire thing using his own enclosure (he's into woodwork and the like).

His enclosure may well be better than the original - it sounds surprisingly good considering their age and intended use. The horn piezo tweeter are equally loud too.
 

Stereodude

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NRG = mc² said:
The speaker is nothing one can't find at any old concert, but I've never seen someone have them in their living room 8)

Two people have a hard time lifting them. They were dismantled, shipped over from the states in the late 70s and then my friend's father re-built the entire thing using his own enclosure (he's into woodwork and the like).

His enclosure may well be better than the original - it sounds surprisingly good considering their age and intended use. The horn piezo tweeter are equally loud too.
I don't quite have any speakers that big, but I've a trick up my sleeve to match the bass level of most "loud" car audio setups. This new subwoofer I'm building should be really interesting. It should be able to do about 132dB in my room at 20Hz. It has 1 15" driver with 72mm of peak to peak travel and 4 15" passive radiators each with 62mm of peak to peak travel. It should make for some interesting videos.

Stereodude
 

Explorer

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flagreen said:
I saw a link to this in another forum and it looked so odd I thought I would post it over here. At first I thought it was a fake looking at the image below, but then the link to A-open seems genuine enough.

I saw a picture (a different one) of that particular mobo a couple if not 3 months ago. Yes, it is for real -- a valve-based audio preamp integrated onto the mobo. Obviously, it's aimed at the custom computer market. I definitely would not have a friggin' valve inside my computer as they are fairly bad about radiating RFI, not to mention the heat -- which would not be too bad with a small pre-amp valve like that.

They still make valves in China. In fact, China -- along with Russia and Yugoslavia -- still have small factories making these devices. The Chinese valves aren't quite as good as the Russian Svetlana valves, but they're good enough.

http://www.svetlana-tubes.com/


It's been or 30 years or more since I've seen one of the machines in a drug store that tests vacuum tubes. Anyone else remember them?...

I still work with valves (er... vacuum tubes, whatever) every once in a while. I own a Marshall "Super Lead Plexi" 100 watt amplifier, circa1975. I pulled 2 of its valves out of its Class-AB output stage a long time ago so that it only operates at a less-than-deafening 50+ watts. It's been working fine for 25 years this way! I've even built from scratch -- back in the mid-1980s -- a wicked little Class-A amplifier using tandem ECC83 pre-amp stages and a EL34 output valve.

 

adriel

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After performing a few key internal component modifications to a mass market grade SACD player, I have arrived at a powerful notion: that "digital" sound, in a negative sense, is not due to limitations in the redbook format but moreso due to poor internal components used inside most cd players. The pity is that decent parts really aren't much more expensive.

Inside Sony's SACD player lineup, increasing internal parts quality is seen as you move up to their more expensive models. However, their lower end models are left with worser parts and thus the creation of the "digital" sound. (Sony, not being a high end company, is not without criticism even in its top model, which uses a relatively poor op amp).

The modifications that I made to the player are actually quite common to that specific model. Black Gate NX HiQ caps to replace the Nichicon FW coupling caps after DAC and also after opamp, Harris FREDs to replace the diode bridge on the power supply board. There are a few more mods I could do, but I'm satisfied for now.
 

Mercutio

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Would you be interested in repeating those modifications on another unit? I've got one of Sony's low-end 5-disc SACD changers (the $150 one) sitting around.

If it makes you feel better, my non-audiophile brother says that his three year old DVD player (back when they were kind of expensive) sounds immensely better for plain old CD playback than his new-ish 5 disc changer. Maybe he's making the same observation you are.

My personal experience is that DVD-Audio is the superior recording format anyway. I think I respond more to the use of multichannel sound from DVD-A's than the supposedly higher quality "analog-ness" of DSD/SACD, which is mostly still a stereo format. Could also be a function of the type of music I enjoy.
 

time

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Adriel said:
... poor internal components used inside most cd players. The pity is that decent parts really aren't much more expensive.
IMO you are spot on, Adriel.

Mercutio said:
I think I respond more to the use of multichannel sound from DVD-A's than the supposedly higher quality "analog-ness" of DSD/SACD
Why else would people buy Bose speakers?
 

adriel

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Would you be interested in repeating those modifications on another unit? I've got one of Sony's low-end 5-disc SACD changers (the $150 one) sitting around.

Is it the CE775? If so, I can give you a schematic and list the capacitor numbers and diode numbers to replace, and link you to where I purchased my parts. The parts cost is $19.29 total after shipping. ($10.40 capacitors (4 quantity) + $3.04 diodes (4 quantity) + $5.85 shipping=$19.29). If you can solder you can do it yourself. The only trick is to mount large FRED diodes onto a board designed for surface mount diodes. If you're unable to void the warranty yourself, I'll do it for you for provided you pay for everything, including shipping both ways, and $5 bucks extra to cover my solder (Cardas), iron tip wear, electricity, gas, and parking at the post office. If you live in my city we don't have to worry about shipping. Otherwise, I shudder to think how much shipping each way would cost...$50 each way? I hope not.

Myself, I use the CE775 unit mostly for cd playback since there's not a lot of SACD material that I like.
 

adriel

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The CE775 has three DACs and three op amps. Modding all channels triples the cost.... I recommend you just mod the two channel DAC and op amp, and use it as a very fine two channel player.

It's no secret how the mods are done. Some folks have gone commercial modding this unit, they install a $200 low jitter clock and other mods and charge money. If it weren't for their helpful feedback on online forums, I wouldn't know which parts were the best to mod without trial and error.

Black Gate capacitors, need 4 of them:

Non-polar NX HiQ 47uF 6.3V, $2.60 each

http://www.referenceaudiomods.com/Merchant2/merchant.mv?Screen=BLACKGATE&Store_Code=RAM

Harris FREDs, need 4 of them:

4A 600V TO-251 Harris < 30ns, $0.76 each

http://www.referenceaudiomods.com/Merchant2/merchant.mv?Screen=DIODES&Store_Code=RAM

If you are facing the unit, the audio board is upside down, in the back-right corner by the RCA jacks. Remove. Replace C401, C501, C316, C317 with Black Gates.

If you are facing the unit, open the tray, then power off the unit so the tray stays open. Then you might choose to wait a few hours. The power supply board is underneath, with big black caps. Remove. Replace D922, D923, D924, and D925 with the FREDs. Snip the FRED lead lengths a bit, insulate the diode body and back plate with heatshrink or electrical tape, match anode/cathode direction, lay them as flat as possible and solder. The left two FRED bodes will overlap.
 

e_dawg

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Adriel,

Very good points from you. I agree with almost everything you have said in this thread. As a former (read: reformed / recovering :) ) hardcore audiophile, I have gone through the various phases of analog/vinyl superiority, high end cabling, tube amplification, etc. and have basically had enough with all the crap from both extremes -- the quackery addicted audiophiles with complete disregard for the laws of physics and psychoacoustics, and the pure scientists who refuse to acknowledge anything that he can't measure on his oscilloscope or prove with a FFT analysis or rigorous mathematical theorem.

You hit the nail on the head particularly with 2 points: (a) the Achilles heel of most CD players is their analog output stages, not their DAC's; and (b) implementation of both analog and digital reproduction technologies is usually the limiting factor -- not the inherent merit of the technology itself.

Nyquist

I know the theorem. It was popular when CD players first became popular. 16-bit, 44.1 kHz audio, they assured us, could capture every single nuance well into the 20 kHz limit of human audio perception. But if you have ever heard SACD or DVD-A, you will swear that this theorem is bullshit. Now, the theorem may be valid, but the few SACD and DVD-A players I have heard sound noticeably better than the vast majority of CD player I have ever heard. This could be due to inferior analog output stages in most CD players or a host of other factors, but I have to wonder whether CD's sampling resolution is really enough. Maybe SACD and DVD-A give you enough "spare" resolution that if your implementation of the digital reproduction process is flawed (and it usually is for affordable players), you can get away with it and still deliver great sound.

Analog/Tubes

They are less accurate and less practical than solid state amplifiers, but I find they do sound better in some cases, and generally like their sound. Remember, just because something is newer and technically superior does not mean it sounds better. There is a subtle warmth, sweetness, and spatial quality that you just have to experience to understand. Great with jazz and vocals, I find. If you've tried it and don't like it, that's fine. But to brush off tubes as old and inferior technology without listening to it or simply because it produces more distortion, less power, and is not as practical as solid state without listening to it... well, you're missing out on a wonderful experience.

Tannin,

I agree about transducers being the weakest link in the audio chain on a macro level. This is generally true, but we have found that amplification and output circuitry continues to be neglected in "mass market" audio -- almost to the point where it is competing with speakers as being the weakest link in the audio chain. Many mass market audio components use cheap IC's and op-amps in their output stages that mangle the audio signal going through them. Power supplies are often poorly regulated and undersized (notice a similarity to vomit boxes yet, Tannin?). Negative feedback is used to mask distortion caused by poor circuit design or cheap components. Power ratings are what sells, so companies will sacrifice sound quality to get a higher wattage rating (Technics Class H+ receivers come to mind) (notice a similarity to external data rate / interface bandwidth numbers here?). Believe it or not, but electronics (the vomit box type you find at mass market stores) are much more of a limiting factor than you think.

Now, since you have brought up a good point about the mechanical limitations of transducers, and the variations/imperfections in the 1-3 dB range, let me bring your attention to an even greater limitation in audio reproduction and psychoacoustic perception: the acoustic properties of your listening area.

Due to the nature of room interactions and standing waves, the acoustic properties of your listening area can introduce variations/imperfections in the 2-10 dB range. Speaker distance from each other, to the walls, to your ears, horizontal angle to your ears, vertical angle to your ears, distance of your listening chair to each wall, reflectivity/absorption characteristics of every mass and surface in your room, etc. -- these can all make signficant (tens of degrees or several decibels) differences in phasing and frequency response at "hundreds" of frequencies.

Of course, this would require rearranging your living quarters around your sound reproduction needs, as well as using unsightly tube traps scattered throughout your room... which is far from practical. But if you want to cover all your bases, you can't leave room acoustics out of any audio discussion.

Myself

So what do I do? That is the question, presumably, after listening to me babble like I know what I'm talking about...

Since I have had to move around quite a bit the last half decade for education and career, it was not practical to ship or buy/sell a room full of audio equipment. Also, I just can't seem to spend a couple hours every day sitting and doing nothing else but listen to music. I just don't have time for that anymore. So, I make do with crappy 192 kbps mp3 audio played through my crappy onboard Realtek 5.1 audio and crappy Klipsch ProMedia 2.1 speakers and call it a day. My "mid/high end" (well, compared to mass market stuff) equipment is sitting in boxes.

All I know is whoever originally stated that 128 kbps is equivalent to "CD quality" should have their ears checked.
 

Stereodude

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adriel said:
The CE775 has three DACs and three op amps. Modding all channels triples the cost.... I recommend you just mod the two channel DAC and op amp, and use it as a very fine two channel player.

It's no secret how the mods are done. Some folks have gone commercial modding this unit, they install a $200 low jitter clock and other mods and charge money. If it weren't for their helpful feedback on online forums, I wouldn't know which parts were the best to mod without trial and error.

Black Gate capacitors, need 4 of them:

Non-polar NX HiQ 47uF 6.3V, $2.60 each

http://www.referenceaudiomods.com/Merchant2/merchant.mv?Screen=BLACKGATE&Store_Code=RAM

Harris FREDs, need 4 of them:

4A 600V TO-251 Harris < 30ns, $0.76 each

http://www.referenceaudiomods.com/Merchant2/merchant.mv?Screen=DIODES&Store_Code=RAM

If you are facing the unit, the audio board is upside down, in the back-right corner by the RCA jacks. Remove. Replace C401, C501, C316, C317 with Black Gates.

If you are facing the unit, open the tray, then power off the unit so the tray stays open. Then you might choose to wait a few hours. The power supply board is underneath, with big black caps. Remove. Replace D922, D923, D924, and D925 with the FREDs. Snip the FRED lead lengths a bit, insulate the diode body and back plate with heatshrink or electrical tape, match anode/cathode direction, lay them as flat as possible and solder. The left two FRED bodes will overlap.
I might have to do this to mine. Except that I would want to do this to all 6 channels rather than just two. Obviously I would need 3 times as many of the BlackGate caps though. Are the other four channels in the same place as the front L & R?

Stereodude
 

Mercutio

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I have the genuinely cheap DVP-NC650V, which is a DVD/SACD player that doesn't play DVDs very well. Are there modification instructions for that one as well?
 

adriel

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Are the other four channels in the same place as the front L & R?

Yeah, they are all on the audio board. Here's the schematic that I downloaded off the internet. If you crop away the white on the .jpg image's tops and bottoms, when printed out each on 1 piece of paper the text will be large enough to read.

http://www.pcez.com/~adriel/Right.jpg
http://www.pcez.com/~adriel/Left.jpg

On the Left.jpg, IC301 is the DAC for the two channel, and C401 and C501 are the output coupling caps. Therefore, it looks like IC302: C421, C521, and IC303: C441, C541.

On the Right.jpg, IC305 is the opamp for two channel, and C405 and C505 are two more output coupling caps. The rest can be figured out for IC306 and IC307 opamps.

The opamp output doesn't ever exceed 3V, which is why 6.3V is fine.

The CE775 comes with a good balance of value. They bothered to use an Elna Silmic cap on the audio board, so some thought was given to quality. Other mods that people are doing are:

-replacing the 47uf caps that supply the opamps, such as C316 and C317 with more capacitance, like Sanyo OSCON 1000uf, 470uf, or more Black Gates. 10V caps are enough since the highest voltage on the board is 7.2V.

-biasing the 2 channel opamp into class A operation using resistors

-Black Gate power filtering caps on the +/- 11V power to the audio board

-low jitter clock for the DAC

I'm personally considering the C316 and C317 mod, but nothing more. Some use Schottky diodes instead of the Harris high speed soft recovery diodes.

The Black Gates changed tone a bit, and removed some edginess such that I could listen at louder volumes. The FREDs seemed to change everything, most noticeably music retrieval and the sound of acoustic guitar. I've recorded before/after sound to the computer. The FRED samples were easier to differentiate compared to the BG samples. I'm not sure what the sound would be like if the FREDs were installed before the BG, since I did them in the reverse order.
 
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