88man, it's not your CD player, if anything, Cambridge 'house sound' is (or at least it was 10 years ago) rolled off in the treble. It's not the excellent Oddysey amp. That amp with Klaus' Lorelei speakers was the hit of a show I once attended.
Your speakers look like a wonderful project but from someone who has built lots of genius speaker ideas that sounded like Doo-Doo, take it from me, build some based on a design that's been tested, measured and has agreement it sounds good: Pi, Audio Note Kits, Madisound, Zaph Audio, etc
Then you won't need band-aid EQ and if you still have the itch to build something that glows, build that Aikido or Tubelab or Bottlehead for the right reasons.
I've had CD's that sounded harsh. I don't know if it's because of the way they were mixed (EQ and mic techniques), or sampling rate related issues, or that I use a relatively cheap CD player (a $150 Panasonic DVD changer). Other CD's sound great. So does the TV and the FM tuner sometimes.
The biggest problems in any system are usually the speakers and the room acoustics. If that can be ruled out, there's the question, "Is the CD player the problem, or is it that other variables make other sources sound better somehow, and the CD player is actually the more accurate source?" How many people do you know who have verified that they have the right capacitive loading on their cartridge? I know zero, and it matters a lot. It will have psycho-acoustic effects on more than just the treble.
If you want "holographic sound", you might want to consider using either a Bob Carver "Holographic Generator" or the Polk Audio approach for inter-aural cancellation. I have both and love them, despite the fact that you've got to position your head in the exact center between the speakers for the effect to work. I turn it off when I have company. Open baffle speakers can synthesize a similar effect artificially to some degree, if the room is right and the speakers are positioned correctly (at least 3 ft. from any walls). Actually, the holographic generator techniques also require that the speakers be distant from any walls to work well. Otherwise you're limited to horizontal axis stereo effect in the upper midrange only, which can be pretty good, but I wouldn't call it "holographic".
I believe that there's a "learned response" that can give a recording a sense of depth (relative delays and reverb) and even height (the ear pinia (sp?) shape for height), but it's mostly on the Z axis, and individuation of instruments is nothing like I get with the "holographic generator" techniques I use.
Sorry if this is way off topic. What was the topic? Oh yea, using the Aikido line stage to get holographic sound. hummm... Any circuit that brings the second harmonic into play could give a sense of depth. Tubes usually do that to some degree. Read what Bob Carver says about tube amps and why he thinks they sound better. The speaker simultaneously acting as a mic, picking up room reflections and feeding that signal into the feedback input port of the poweramp, to mix with the program source signal.
The biggest problems in any system are usually the speakers and the room acoustics. If that can be ruled out, there's the question, "Is the CD player the problem, or is it that other variables make other sources sound better somehow, and the CD player is actually the more accurate source?" How many people do you know who have verified that they have the right capacitive loading on their cartridge? I know zero, and it matters a lot. It will have psycho-acoustic effects on more than just the treble.
If you want "holographic sound", you might want to consider using either a Bob Carver "Holographic Generator" or the Polk Audio approach for inter-aural cancellation. I have both and love them, despite the fact that you've got to position your head in the exact center between the speakers for the effect to work. I turn it off when I have company. Open baffle speakers can synthesize a similar effect artificially to some degree, if the room is right and the speakers are positioned correctly (at least 3 ft. from any walls). Actually, the holographic generator techniques also require that the speakers be distant from any walls to work well. Otherwise you're limited to horizontal axis stereo effect in the upper midrange only, which can be pretty good, but I wouldn't call it "holographic".
I believe that there's a "learned response" that can give a recording a sense of depth (relative delays and reverb) and even height (the ear pinia (sp?) shape for height), but it's mostly on the Z axis, and individuation of instruments is nothing like I get with the "holographic generator" techniques I use.
Sorry if this is way off topic. What was the topic? Oh yea, using the Aikido line stage to get holographic sound. hummm... Any circuit that brings the second harmonic into play could give a sense of depth. Tubes usually do that to some degree. Read what Bob Carver says about tube amps and why he thinks they sound better. The speaker simultaneously acting as a mic, picking up room reflections and feeding that signal into the feedback input port of the poweramp, to mix with the program source signal.
Last edited:
Bob,
I think yours is a good summary of what we are really dealing with here: A desire that actually has more to do with set-up and aural factors than with actual components; an 'image' experienced by everyone differently, depending rather little on the electronic elements in the total mix. I think that has been settled (although one still marvels at the incredible abilities afforded to amplifiers to have anything to do with depth, space, commitment, etherealness/ethereality. (You off-topic? Hardly. It was clear that the OP was after a holographic 'something', and innocently started by asking about one element in the whole scenario. Only some seem to have been incapable of grasping this through whatever mindset limitations ....)
I myself have experienced a momentary holographic sensation in certain set-ups which I was incapable of recreating in my own room afterwards, but in hunting for which I came across other surprises. As you say, the recording shenanigans are outside one's control. My taste is mainly classical and there (perhaps fortunate for me?) I seem to have been spared poor recordings. But even good recordings differ in 'realism' effect - and let us not start on the recording studio phenomena.
By now the OP should be at peace with most decent electronics, and perhaps go hunt among set-ups for the elusive goal. The arrangments by others, patiently experimenting with his own, including with room appointments ......
Again, I wish him good fortune!
I think yours is a good summary of what we are really dealing with here: A desire that actually has more to do with set-up and aural factors than with actual components; an 'image' experienced by everyone differently, depending rather little on the electronic elements in the total mix. I think that has been settled (although one still marvels at the incredible abilities afforded to amplifiers to have anything to do with depth, space, commitment, etherealness/ethereality. (You off-topic? Hardly. It was clear that the OP was after a holographic 'something', and innocently started by asking about one element in the whole scenario. Only some seem to have been incapable of grasping this through whatever mindset limitations ....)
I myself have experienced a momentary holographic sensation in certain set-ups which I was incapable of recreating in my own room afterwards, but in hunting for which I came across other surprises. As you say, the recording shenanigans are outside one's control. My taste is mainly classical and there (perhaps fortunate for me?) I seem to have been spared poor recordings. But even good recordings differ in 'realism' effect - and let us not start on the recording studio phenomena.
By now the OP should be at peace with most decent electronics, and perhaps go hunt among set-ups for the elusive goal. The arrangments by others, patiently experimenting with his own, including with room appointments ......
Again, I wish him good fortune!
Thanks for the good ideas! Agreed Jean-Paul, it's difficult to control the direction of any thread, but I am thankful for the great ideas in a open round table type discussion, be it over "tea" or beer. 
Feel free to change the title to "Tube Preamp: Remedy For Digital Glare? Sources Of System Weaknesses."
When I started the thread, I thought that having a tube preamp in the chain could provide a neutral and holographic sound, and the Aikido seemed like an easier project. I didn't address digital glare from the outset because I just assumed that the inherent "warm" nature of some tubes could tame digital glare as a byproduct. I know I am not the only one who hears digital glare, nor am I the first to assume "tube treatment" as a possible remedy.
I've been testing my speakers alongside Paradigm S40, S20, Pioneer Quartet 70. All the speakers exhibit digital glare on solo piano music. Differences in the parallel and series fed crossovers was quite noticeable in this test. Compared with other speakers, the DIY series fed crossover has more presence, forward, dynamic, musical, and transparent sound. On vocals, it sounds magical with air, openness, presence. But on piano recordings, the digital glare is there especially in 700-1kHz range. The RTA revealed peaks at 700-900Hz (2dB), 2kHz (1.5dB), 3kHz (1.5dB). Amazing how much 2dB makes in the mids.
Then I decided to vary the value of the tweeter attenuation resistor from 0.68 to 0.82 Ohm. Digital glare improved slightly with a nice balance using 0.75 Ohms. The "digititis" is more tolerable now. Then I changed the Mundorf Supremes to Rike Audio S-Caps PIO, and all the MOX to a Jantzen Superes, and the Mundorf L200 coils to Jantzen wax foils. Wow! It's as if I switched from digital to analog! The digital glare was even more tolerable, and the piano registers were clear with no stridency. Spatial imaging, air, and transparency is the same, but somehow there is less grain than before. Below is a plot of the impedance and phase.
As what Bill, Bob, and Johan said, I'd like to build a tube preamp, buffer, or phono stage at some point. I have to make something with all the tubes I've collected.
Feel free to change the title to "Tube Preamp: Remedy For Digital Glare? Sources Of System Weaknesses."When I started the thread, I thought that having a tube preamp in the chain could provide a neutral and holographic sound, and the Aikido seemed like an easier project. I didn't address digital glare from the outset because I just assumed that the inherent "warm" nature of some tubes could tame digital glare as a byproduct. I know I am not the only one who hears digital glare, nor am I the first to assume "tube treatment" as a possible remedy.
I've been testing my speakers alongside Paradigm S40, S20, Pioneer Quartet 70. All the speakers exhibit digital glare on solo piano music. Differences in the parallel and series fed crossovers was quite noticeable in this test. Compared with other speakers, the DIY series fed crossover has more presence, forward, dynamic, musical, and transparent sound. On vocals, it sounds magical with air, openness, presence. But on piano recordings, the digital glare is there especially in 700-1kHz range. The RTA revealed peaks at 700-900Hz (2dB), 2kHz (1.5dB), 3kHz (1.5dB). Amazing how much 2dB makes in the mids.
Then I decided to vary the value of the tweeter attenuation resistor from 0.68 to 0.82 Ohm. Digital glare improved slightly with a nice balance using 0.75 Ohms. The "digititis" is more tolerable now. Then I changed the Mundorf Supremes to Rike Audio S-Caps PIO, and all the MOX to a Jantzen Superes, and the Mundorf L200 coils to Jantzen wax foils. Wow! It's as if I switched from digital to analog! The digital glare was even more tolerable, and the piano registers were clear with no stridency. Spatial imaging, air, and transparency is the same, but somehow there is less grain than before. Below is a plot of the impedance and phase.
As what Bill, Bob, and Johan said, I'd like to build a tube preamp, buffer, or phono stage at some point. I have to make something with all the tubes I've collected.
Attachments
Last edited:
88man
Go build that Aikido LS or ACF-2 or whatever, and "Just because I want to" is the best motivation for it. Never try to build audio equipment as a fix for some problem in your system . Audio companies spend millions of dollars on R&D to develop a specific sound signature for their equipment, and still get it wrong.
I am building my Aikido and Tetra, and my motivation is "Just because I want to".
Go build that Aikido LS or ACF-2 or whatever, and "Just because I want to" is the best motivation for it. Never try to build audio equipment as a fix for some problem in your system . Audio companies spend millions of dollars on R&D to develop a specific sound signature for their equipment, and still get it wrong.
I am building my Aikido and Tetra, and my motivation is "Just because I want to".
One of the main reasons I see that audio systems get it wrong, is that they often exclude good tone controls (I use a 4 section Baxandall), and they can only guess at what the listening room acoustics will be like. Also, many designers these days may be sharp at digital but not so sharp at analog circuit engineering. For example, how many preamps or poweramps have a passive Rf filter at their inputs? Can the amp deal with Rf well? No, they can't. At least one of the Behringer products (a digital crossover) has a polarized electrolytic in series with the analog input without bias, and an opamp is driving a load of about 400 ohms. The differential output of their DAC is picked up by an unbalanced buffer... The specs they list on paper look good, but the reality is quite different. Most manufacturers don't care. It's all about the dollar. That's one of the reasons I build most of my system myself.
Last edited:
I totally agree. It's sad to see what gets left out to save just a couple of bucks. A permanent (no bypassing) NTC inrush protection in a Behringer poweramp in another example. Sigh.
I'm very interested in the 4 section baxandall tone control! Do you mind sharing a schematic?
Yeah, more like the early days of telephony. More than 6 kHz and the highs were terrible.
Shotgun at the barn door comments on the thread to date:
I use a Joe Rasmussen modded Onkyo CD Player. It has the VSE TeraFirma Clock but the mod I think makes the most difference is that the entire audio output stage has been deleted and replaced with an 1:1 high quality (nickel core) audio transformer driven straight of the voltage output DAC. That drives my tube Power Amp directly (6SL7 / 6V6 Baby Huey).
I went out and bought a Digital Radio Tuner recently - what a horrible waste of money, its sound quality is "unlistenable". The level of digital compression used to pack in the extra information (whats up next, current weather report etc.) is way in excess of anything we should have to tolerate. Then I don't much like MP3 either but its is no where near as bad as DAB.
I spent a lot of time in the sand box building and modifying SS Amps. If there was one lesson I learned thoroughly from that it is that introducing second harmonic distortion is great at "masking", "covering up" a multiude of audio sins BUT treating the disease and not the symptoms by curing those multitude of audio sins always gave superior results and obviated the need for the added "masking" 2H distortion.
Example: I ran Riken Ohm Carbon Comp resistors as the VAS load resistor (bootstrapped) and in the feedback path to make the amp sound nice and warm (by introducing some 2H distortion). Once I fixed the problems that were causing the cold harsh sound that the Rikken Ohms "addressed" then the Rikken Ohms themselves became objectionable.
I would urge you to address the real problems. Identify if it is your speakers, your sources, your preamp, your power amp which is the problem and target your fixes/upgrades. Simplifying your system will always help, if you don't need a preamp/linstage then don't use one. Despite what I said above I do believe in using tubes to modify the sound in what to me is a pleasant way but don't overdo it. If using a tube power amp there is no real reason to also use a tube preamp. If you are just adding a tube preamp / linestage to warm up your sound or address the digital artefacts /short commings of your source then you applying your efforts and money in the wrong place.
So donning my flameproof vest in anticipation ......
Cheers,
Ian
I use a Joe Rasmussen modded Onkyo CD Player. It has the VSE TeraFirma Clock but the mod I think makes the most difference is that the entire audio output stage has been deleted and replaced with an 1:1 high quality (nickel core) audio transformer driven straight of the voltage output DAC. That drives my tube Power Amp directly (6SL7 / 6V6 Baby Huey).
I went out and bought a Digital Radio Tuner recently - what a horrible waste of money, its sound quality is "unlistenable". The level of digital compression used to pack in the extra information (whats up next, current weather report etc.) is way in excess of anything we should have to tolerate. Then I don't much like MP3 either but its is no where near as bad as DAB.
I spent a lot of time in the sand box building and modifying SS Amps. If there was one lesson I learned thoroughly from that it is that introducing second harmonic distortion is great at "masking", "covering up" a multiude of audio sins BUT treating the disease and not the symptoms by curing those multitude of audio sins always gave superior results and obviated the need for the added "masking" 2H distortion.
Example: I ran Riken Ohm Carbon Comp resistors as the VAS load resistor (bootstrapped) and in the feedback path to make the amp sound nice and warm (by introducing some 2H distortion). Once I fixed the problems that were causing the cold harsh sound that the Rikken Ohms "addressed" then the Rikken Ohms themselves became objectionable.
I would urge you to address the real problems. Identify if it is your speakers, your sources, your preamp, your power amp which is the problem and target your fixes/upgrades. Simplifying your system will always help, if you don't need a preamp/linstage then don't use one. Despite what I said above I do believe in using tubes to modify the sound in what to me is a pleasant way but don't overdo it. If using a tube power amp there is no real reason to also use a tube preamp. If you are just adding a tube preamp / linestage to warm up your sound or address the digital artefacts /short commings of your source then you applying your efforts and money in the wrong place.
So donning my flameproof vest in anticipation ......
Cheers,
Ian
Last edited:
Never a truer word spoken.
If the cd player is giving you grief due to digital glare, either change the cd player, modify it, or don't use it at all. Anything down the audio chain is not going to assist if the problem is there right at the outset.
That said, if you do build the Broskie, pair it with a nice solid state amp, ditch the cd player and use a computer based set up, you'll probably have a simpler system, less clutter in the house (happy wife), and an excellent sound.
I've got a 6V6 tube amp, and a solid state amp, and the aikido doesn't sound any good with the 6V6 amp (which is giving me a whole other world of pain..different story), but the aikido is sheer magic with a good solid state amp!
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.