• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

I need some help and answers!!

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I have been looking all around for something like the Musical Fidelity X-10D which is something like a line preamp or processor for cd players and d/a converters to give digital media that warm analogue sound.

Does anyone have any schematics for such a device? And if so, do you have any advice on which valves would sound best?

Since my father has been building tube radios ever since he was a kid and knows tubes inside and out, and has agreed to build this for me, I would really like to help him out as much as possible as far as the design and all.

Any help will be greatly appreciated!

Thanks in advance. ;)
 
Ex-Moderator
Joined 2003
chops said:
I have been looking all around for something like the Musical Fidelity X-10D which is something like a line preamp or processor for cd players and d/a converters to give digital media that warm analogue sound.

Hmmm. I wonder what your feelings are on electronic organs?

Anything that changes the sound of digital in the analogue domain must be adding distortion. If you want analogue sound, then perhaps it should come from analogue? Alternatively, perhaps you need better implemented digits? You might want to try asking about better digits over on the digital forum...

I realise this doesn't directly answer your question, but I don't think deliberate distortion will help.
 
Re: Re: I need some help and answers!!

EC8010 said:


Hmmm. I wonder what your feelings are on electronic organs?

Anything that changes the sound of digital in the analogue domain must be adding distortion. If you want analogue sound, then perhaps it should come from analogue? Alternatively, perhaps you need better implemented digits? You might want to try asking about better digits over on the digital forum...

I realise this doesn't directly answer your question, but I don't think deliberate distortion will help.

Deliberate distortion?! All I can say is that the one X-10D I have heard and a few cd players with built-in tube stages that I have listened to did not have any distortion. They actually sounded quite fine.


ShiFtY said:
You could try a dual triode linestage: just add muliple inputs, a selector switch, volume control and a couple of valves! Use a tube rectifier. There are many good schematics available.

Try this for some ideas: http://www.the-planet.org/linestage.html

and http://www.bonavolta.ch/hobby/en/audio/audioel.htm

Thanks for the great links! I will be going back to those sites to read them fully after I'm done here! ;)


fdegrove said:
Hi,

The X10-D has been discussed twice already on the forum.

LATEST DISCUSSION.

Cheers,;)

Ummm.... I do believe I know how to use the forum search button. If I found anything useful for me, don't you think I would have posted there instead of starting my own thread here with completely different questions?!
 
As you can see from the pictures below, my father is quite capable of building tube radios and takes great pride in his work.

He has also built a few stereo tube amps and preamps in the past, but that was a long time ago, so he claims to be a little rusty when it comes to hifi gear, hence the reason I want to fine some schematics for him.

This radio here was just built, from scratch no less. It has a solid wood chassis, four tubes, and 8 different plug-in windings for various short-wave bands. Now you can see why I would like him to build me my little project! :bigeyes:

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
Wow now that is what I call beautiful!

Thanks for sharing those pics...

PS does your dad have any schematics for a simple FM radio...that uses tubes?

Now back to your questions..

The MF X10 uses a very common tube ECC88. Dad will know. Now I don't know what type of setup the ECC88 is used as. But if I wanted to do what MF tried to do I would not use an ECC88. But rather a 2A3 or something. Or even a 6AS7 or the likes. There is a 6AS7/6080 preamp schematic on the net. One is quite simple the other uses output transformers and batteries it is a more of a hi-end type setup (This is Christian Rintelen's)...would not build that one..

Am sure a 6as7 preamp will return lots of google hits...mmm one thing I found was this..by Bob Danielak

"i did a crazy resistor loaded line stage using a single 6as7/6080.

the thought was to make a hi-current amp with practically unity gain.

i ran them at something like 130V / 80mA.
1.5K or 2K resistive load. 2uF out.

got like 1.2X gain...

didn't sound like anything. no difference with or without.
i was hoping to warm up my CD output a little (given the high D2
of the 6as7).

nada.

i still have it laying around. figured if i ever had to drive a few miles
of cable, it'd be good to have available.

neat little 4" x 6" x 3" package, too.

bob.d. "

So it is actually quite hard..cause a tube is actually a very neutral amplifying device...

But try it..Grover had some succes...

"Bob's experience with a 6AS7 line
stage sounding like "nothing" doesn't surprise me. Not the romance one
might be seeking from DHTs, but OTOH remarkable BW and capable of real
sweetness if they're set up properly.

I hear a very different different harmonic texture which takes some
adjustment compared to a DHT, but if you give them time and keep a good
"attitude" :) these tubes can offer some pretty cool sounds.

Grover Gardner"

PS..I find the 6AS7 very warm with very smooth liquid highs...;)

Don't puke fellow boarders...don't know how else to describe it.:cannotbe:

Regards,
Bas
 
diyAudio Senior Member
Joined 2002
DR. EVIL.

Hi,

Ummm.... I do believe I know how to use the forum search button. If I found anything useful for me, don't you think I would have posted there instead of starting my own thread here with completely different questions?!

It was my understanding you requested the circuit diagram for the MF X10-D.

Dr.Evil has decided you won't get it.:mafioso:
 
diyAudio Senior Member
Joined 2002
Barf.

Hi,

Using 10 6AS7G/6080s per channel in my amps and having tried several sources I can only say that both sources could be correct,

I had some old NOS 6AS7Gs that really sounded, errrr....like radio nostalgia: too sweet and dull.

Generally speaking this tube is a formidable performer with no sound I can think of...

So, in conclusion I think Bob Danielaks' description is more accurate.

Of all triode DHT powertube tubes it certainly is one of my favs.

Cheers,;)
 
This is close to what I would like to do to my DAC8. The only thing is, the d/a converter for the Nad cd player is a Sigma-Delta. Mine is a..... well, I'm not sure what it is exactly. All it says in the manual is that the "Resolution" is 18 bits.

Maybe someone can figure something out! ;)

An externally hosted image should be here but it was not working when we last tested it.


I found this and other various interesting projects at UltraAnalog
 
Re: Barf.

fdegrove said:
Hi,

Using 10 6AS7G/6080s per channel in my amps and having tried several sources I can only say that both sources could be correct,

I had some old NOS 6AS7Gs that really sounded, errrr....like radio nostalgia: too sweet and dull.

Generally speaking this tube is a formidable performer with no sound I can think of...

So, in conclusion I think Bob Danielaks' description is more accurate.

Of all triode DHT powertube tubes it certainly is one of my favs.

Cheers,;)

Aren't the 6AS7G and 6080 tubes indirectly heated??
 
One other thing I found out last night on the internet, AMC apparently made a DAC9 with guess what?... A tube output stage!

However, I could not find any reviews or articles on the DAC9, or specs for that matter. In fact, I couldn't find much of anything about the DAC9.

So, in the long run, I think it would be better to do a DIY project out of the DAC8, since I would have control on what goes into it as far as parts and the like.

I am going to be opening it up today to check out the innards and snap some shots. If anyone is interested, I will post a few of them if you think that might help some.

I am also going to be looking into doing some tweeks to it like upgrading the RCA jacks to good quality gold ones that bolt to the chassis, possible upgrading some internal wiring, and maybe even upgrading the psu. (I'm not too sure about that last one yet though.)

Is there any thoughts or ideas on what to look for when I open it up? What about the # code on the DAC chip or the clock? Anything else anyone can think of, please let me know about it! ;)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.