[dBel84]

Quote:

Originally Posted by 04BluMach /img/forum/go_quote.gif I have been anxiously awaiting further info on Runeight's "Super" SOHA and of course its final unveiling. .... TOMB do you have any personal insight or knowledge on the status of Runeight's SOHA?

not to thread-jack but rumours spread so quickly ... it has gone through several design phases and after a few distractions has been finalised. The concept amp sounds phenomenal and so should SOHA II which is in prototype phase. runeight will post more news in good time.

Quote:

Originally Posted by 04BluMach /img/forum/go_quote.gif I believe also that John Broskie has a low voltage 6GM8 version of his Akido available.

Runeight has not been completely idle .. The EHHA is a low voltage tube amp which utilises the 6GM8. I have it biased 150mA into class A - I don't need a heater in my office

..dB

 

[amphead]

Update: Specifying (12AE6A) 2 GE and 2 RCA with Sylvania as a third choice, I received 2 RCA (side halo) and 2 Sylvania(trapezoidal getter). So this is the availability from Tube Depot currently. Popped the Sylvanias into the functional Max expecting a lesser tone and........very nice! Don't be afraid to use Sylvanias.

 

[tomb]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Update: Specifying (12AE6A) 2 GE and 2 RCA with Sylvania as a third choice, I received 2 RCA (side halo) and 2 Sylvania(trapezoidal getter). So this is the availability from Tube Depot currently. Popped the Sylvanias into the functional Max expecting a lesser tone and........very nice! Don't be afraid to use Sylvanias.

Yes - you're right. In my experience, the Sylvania 12AE6 probably has the best highs of any 12AE6. I'm a certified bass head, though, and they seemed to lack the punch of the GE's.

Also, Amphead - your post emphasizes a good point. Just because the MAX has those killer DB's and a lot of our discussion has been on BG's, ES's, VitQ's, K42's, etc. - that doesn't mean that tube changes aren't noticeable. Rolling tubes in the Millett is a worthwhile effort and may effect a large part of the sound of the amp.

Rolling is a bit more difficult in a Millett, however, because the tubes were so widely sub-contracted from one company to the other. RCA's telltale is the squished octagon with the tube designation. GE's are the etched dots. The other mfr was either Sylvania or Tung-Sol - or both. There's a very good web page by Jeff Duntemann that explains many of the space-charge tubes:

Space Charge Tubes: Tube Projects Without Lethal Voltage!

On this page, he states that Tung-Sol was the originator of the space-charge tubes, so maybe they have to be the other mfr. Tung-Sol Millett tubes seem to have the most "air" IMHO, but they also seem to be the most scarce. I've always had trouble believing that they were the 3rd or 4th mfr of these tubes because of their scarcity. I suppose research and development doesn't parallel manufacturing ability.

Colin also clued me into another tube on this list: the 12FT6. It appears to be a one-to-one equivalent of the 12AE6 (unlike the 12AJ6 which has a gain of 55!). Another one for you guys to investigate, neither Colin nor me have found it listed at any tube vendor. I even sent an e-mail to Dale and Roy at Radio Electric Supply (vaccumtubes.net):

Thomas,

Must be a really obscure tube. We have never seen one, but it is in the databases. I sure wouldn't engineer anything around it. You would have a really tough time finding replacement tubes.

Dale

Let me know if any of you spot one.

 

[amphead]

Yeah, I noticed exactly the same signature change with the Sylvanias, lots of detail, tight recessed bass, but most importantly no "mid bloom". The RCAs that I tried were more punchy/dynamic and very good overall. Where we go down the road, will depend on our tube availability and future circuit design breakthroughs.

 

[joneeboi]

Update on my MAX:

Changes:
- CA2/7 Panasonic FC 1000uF to Black Gate Standard 1000uF
- CA4/5 Nichicon UPW 470uF to Panasonic FM 1800uF
- Removed CA8/9

Glittering Generalities:
- More minute bass detail passed through to my ears and brain
- Soundstage changed (wider?)

Burning it in as I leave for a party soon

(stupid finals...*grumble*)

 

[jerrygp]

This is not the correct forum for this, but I searched the computer-as-source forum and could find no help. Can someone pm me and explain what a DAC's function is in a computer audio environment? As far as I've been able to decipher, it converts digital information to analog information for the purpose of what? I have a high end home audio system and a high end self built computer with sound card, but mainly get my audio through headphones via an IAudio X5L and a number of DIY headphone amps - the Millet Hybrid being one of them. Does a DAC fit into this scenario at all or is it strictly for providing a signal to a home preamp or amp setup through a computer cd player or some sort of cd transport system? I know this is not the right forum for this question and if someone can point me to the right place, I would appreciate it. I am trying to further my audio education at the expense of you guys...

 

[amphead]

Well, you are almost there. Yes a dac is a (digital to analog converter). There are dac's and then there are DAC's. The quality of the conversion process impacts the resulting sound greatly. What conversion process you ask? Well digital encoded audio is ones and zeros, which are square waves. Analog signals are variations of sine waves, which transmit frequencies of sound. Therefore using a mathematical algorithm, the digital square wave is transformed into the analog waveform. Speakers/headphones work with analog waveforms, to produce sound, where voltage is converted to current in the amplifier, to move the coil of the headphone/speaker which in turn pushes air to give you music. Interestingly enough there may be a tube dac project coming this spring. That would be a DAC!!!!!

 

[tomb]

Quote:

Originally Posted by jerrygp /img/forum/go_quote.gif This is not the correct forum for this, but I searched the computer-as-source forum and could find no help. Can someone pm me and explain what a DAC's function is in a computer audio environment? As far as I've been able to decipher, it converts digital information to analog information for the purpose of what? I have a high end home audio system and a high end self built computer with sound card, but mainly get my audio through headphones via an IAudio X5L and a number of DIY headphone amps - the Millet Hybrid being one of them. Does a DAC fit into this scenario at all or is it strictly for providing a signal to a home preamp or amp setup through a computer cd player or some sort of cd transport system? I know this is not the right forum for this question and if someone can point me to the right place, I would appreciate it. I am trying to further my audio education at the expense of you guys...

You had it right - it converts digital information to analog information. There are many esoteric uses for any device that serves as a source for digital music files. Connect a DAC with compatible inputs for the source's outputs, and it will convert those digitial files to analog. Most high-end DACs also include an elaborate I/V conversion, because a DAC in its purest form outputs small levels of current - way too low to be used as a source for most audio equipment.

But that's getting too far into the nits. In it's most prevalent use (IMHO), it allows the use of a computer as your primary music source. Connect a DAC to your computer - then mp3 files, FLAC files, wav files, CD drives, etc. - may be used to connect directly to your preamp or headphone amp setup. In simple terms, it serves the same purpose as your computer's sound card, but at a much, much higher level of detail and quality.

For instance, a high-end quality DAC will easily blow away any sound card. Even a low-end DAC, such as the Alien DAC, will better most all built-in sound cards and some after-market sound cards. I don't have super-expensive sources - mostly Sony and Technics CD and DVD players, both portable and home component versions, and a few iPods. However, my Alien DAC blows away all of them in sound quality with superior detail and frequency response. Only a line-out iPod comes close. An M-Audio Transit is comparable - better in noise, but not in detail, IMHO. For instance, all I listen to with my Millett MAXes are FLAC files on the computer played through Foobar and an Alien DAC connected via a USB cable.

You can imagine my excitement when you realize that the Alien is down at the bottom of quality for most DACs - so there's huge improvements to be had.

You'll also see DAC's used in high-end systems where CD players or DAPs are used as transport mechnisms only. They'll have digital outs such as optical or SPDIF for use in connecting to a separate component DAC, where the signal is converted to analog and lifted to line levels. The combination serves as high-quality source to your preamp or headphone amp systems.

EDIT: Yes, Amphead is correct - there's some exciting stuff coming, especially in DACs. DIY has only scratched the surface in DAC technology.

There are a couple of MAX builders who've placed a DAC directly in the case with a MAX. For instance, Pabbi just posted pics of his balanced MAX with an OPUS DAC as the source in the same case. All he has to do is connect a PC or CD transport directly, I believe. Some have built simpler versions that just have a USB plug on the back of a MAX in addition to RCA connectors. Connect a USB cable between the MAX and your PC, fire up Foobar or some other Media Player and away you go.

 

[willisv]

You wouldn't be able to plug your IAudio X5L into a standalone Dac because it doesn't have a digital output. But you could bypass the dac in your sound card by plugging in an alien dac or something similar to the usb port in your computer and then into your amplifier. This would give you better quality sound than your IAudio X5L could provide.

 

[amphead]

Yeah, good point Willisv! He needs to bypass that sound card, and use an Alien dac as TomB mentions in his post. Great explanation TomB! I think that puts to bed any gaps in knowledge that anyone had. btw, look at my post count.

 

[willisv]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Yes - you're right. In my experience, the Sylvania 12AE6 probably has the best highs of any 12AE6. I'm a certified bass head, though, and they seemed to lack the punch of the GE's. Also, Amphead - your post emphasizes a good point. Just because the MAX has those killer DB's and a lot of our discussion has been on BG's, ES's, VitQ's, K42's, etc. - that doesn't mean that tube changes aren't noticeable. Rolling tubes in the Millett is a worthwhile effort and may effect a large part of the sound of the amp. Rolling is a bit more difficult in a Millett, however, because the tubes were so widely sub-contracted from one company to the other. RCA's telltale is the squished octagon with the tube designation. GE's are the etched dots. The other mfr was either Sylvania or Tung-Sol - or both. There's a very good web page by Jeff Duntemann that explains many of the space-charge tubes: Space Charge Tubes: Tube Projects Without Lethal Voltage! On this page, he states that Tung-Sol was the originator of the space-charge tubes, so maybe they have to be the other mfr. Tung-Sol Millett tubes seem to have the most "air" IMHO, but they also seem to be the most scarce. I've always had trouble believing that they were the 3rd or 4th mfr of these tubes because of their scarcity. I suppose research and development doesn't parallel manufacturing ability. Colin also clued me into another tube on this list: the 12FT6. It appears to be a one-to-one equivalent of the 12AE6 (unlike the 12AJ6 which has a gain of 55!). Another one for you guys to investigate, neither Colin nor me have found it listed at any tube vendor. I even sent an e-mail to Dale and Roy at Radio Electric Supply (vaccumtubes.net): Thomas, Must be a really obscure tube. We have never seen one, but it is in the databases. I sure wouldn't engineer anything around it. You would have a really tough time finding replacement tubes. Dale Let me know if any of you spot one.

These guys may have this tube in stock (12FT6), It's listed on their site. I was going to give them a call but I'm over budget this month.

Leeds Electronics : Tubes 8KA8 - 12HG7

 

[jerrygp]

Thank you folks for the valued info. I'm in the process of building a new PC and haven't purchased a sound card yet or know yet if I even need to, but have a solid motherboard/cpu/memory configuration. I've been reading posts in different forums about how to "best get the most" out of the various audio processing and playback choices I will have to be making. So many choices to make. I need a mentor. I mentor at work and never thought I would need one myself. Should have been boning up on audio when I was younger instead of some of the crazy other stuff. I'm fortunate that so much info is available online. I just gotta keep reading and asking questions and maybe I will get lucky and have the right amount of skill to put something together that pleases my ears and intellect, and scratches that itch I have and the folks in this forum have to create.

 

[amphead]

Hey TomB, the Bijou looks interesting! A nice addition to the Millett Max collection.

Look at my post count fellow Head-Fiers!

 

[tomb]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Hey TomB, the Bijou looks interesting! A nice addition to the Millett Max collection.

Don't know about that. Maybe you meant something else, but the Bijou is not affiliated with the MAX, the Millett, Colin or myself.

EDIT: Your post count looks good, though!

 

[jamess71]

Quote:

Originally Posted by amphead /img/forum/go_quote.gif Look at my post count fellow Head-Fiers!

Congrats on the 1500. Man Im a long way off. 10X and i'm there.....

I got the rest of my parts in yesterday for my holiday max X 2 build. I ended up getting 10 - 12FK6 from ? man now I can't remember. I'll check tonight. It wasn't VacuumTubes.net though. He said someboby built a board back in the spring that used these tubes and they have been selling like hotcakes ever since.

I wonder what that board was....

He said they probably didn't sell 1 in 7 years prior to the MM. He does have a few mix and match left.