rowemeister said:Hi all.
I have done a mod which many of you will just laugh at
And its no where near has complex as the tube mod, but I am keeping an open mind.
The LED mod
I will test this fully to see if there is any difference.
Wooow, ----pimp my player----
I know a fellow-DIY'er that put green LED's in his player and told me the bass had improved considerably. He also uses the greem marker on the edges of his cd's. I haven't had the chance to hear the differences, but if you detect any, i'm going to try it too
.Ray.
poynton said:
Hi.
Another day .....had to repair the power supply this morning - somehow the Tx developed a primary short. Luckily I had a New TX to hand so I could repair it.
Worth the wait though !!!!!!!!!
Now using one of the minature tubes ( 6BF7W ).
Really excellent sound - possibly a little lighter on the bass than the E88CC but only a RCH !
B+ is incredible - it does not seem to distort (audibly) until B+ goes down to 3.5v - Correct 3.5v !! then it cuts off anyway ! I will keep it at B+ = 25v - audible performance does not seem to improve above this.
Heater is running a bit bright for my liking and gets HOT. I will try on 5v regulated supply rather than 6.3v AC
Andy
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6h5c said:
Hi Ray,
Do you still have the hiss??
I have been playing with the latest incarnation with interesting results!
Refering to Thorsten's circuit...
I used a probe connected to my amp at various points.
I could only detect significant hiss at the input at the junction of the choke and the DAC output ( where you would expect - no filtering whatsoever).
The interesting part is that after the choke, some hiss, slight buzz - and perfectly acceptable music !
Have I just found the ultimate minimalist mod?? straight off the DAC with a filter - no op amps, tubes etc??
Try it.
Andy
Hi Andy!
Nice results! Especially at this low voltage.
Did you use a current sink for the kathodes, or a resistor?
You really got me going on this!
I went to the dump-store this afternoon, and I picked up some 5672 and 6418 pencil-tubes. They are low-voltage direct-heated penthodes that use 1,25V heater supply! I don't know if they're any good, but one of them has got very nice triode characteristics!
As soon as I have the passive part finished i'm going to try them.
Regards,
Ray.
Nice results! Especially at this low voltage.
Did you use a current sink for the kathodes, or a resistor?
You really got me going on this!
I went to the dump-store this afternoon, and I picked up some 5672 and 6418 pencil-tubes. They are low-voltage direct-heated penthodes that use 1,25V heater supply! I don't know if they're any good, but one of them has got very nice triode characteristics!
As soon as I have the passive part finished i'm going to try them.
Regards,
Ray.
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poynton said:
Yes, it is still there. But it is not audible with music playing. I only noticed it when I turned the volume of my amp to 100%, to see if the tubestage was humming/making noise. But my CD63, which uses the standard opamps + filter also produces the same hiss. So I THINK it is a HF residue caused by the DAC. It was about 22mV in amplitude, and Brent also measured it. Did you check with a scope yet?
poynton said:
Ehm, a shop with lots of junk, where they sell old army stuff and surplus parts, I don't know the exact word in english. They have at least two boxes full of these, they only cost me € 1,00 each! So I bought four of both types.
Ray.
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This, for example:
http://www.military-tubes.com/index_en.html
When you have good luck, you find sometimes under the label "sub-micro tubes" 250g tubes for 5 Euro!
I ordered 500gr and got more than 160 tubes:
Many 6021, 6111, 6112 double triodes. And many 5702, 5636 and some other pentodes, and Diodes, Regulators and so on.
Franz
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Hi Franz,
Cool site! I love those places.
I'm very glad I have a place like that about half an hour driving from where I live. It's called "BACO". I go there like once in a month to check if they have new things. They have a (dutch) website too: http://www.baco-army-goods.nl/
This is my tube-collection so far. About half of it (and the boxed ones) comes from the dump-store, and the other half is old TV tubes (PL series).
Ray.
Cool site! I love those places.
I'm very glad I have a place like that about half an hour driving from where I live. It's called "BACO". I go there like once in a month to check if they have new things. They have a (dutch) website too: http://www.baco-army-goods.nl/
This is my tube-collection so far. About half of it (and the boxed ones) comes from the dump-store, and the other half is old TV tubes (PL series).
Ray.
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ray
got the pdf with the pcb layout
awesome! thank you very much
something to investigate while i'm waiting for the tent clock.
rowemeister
HF signal - Data Signals, how about cat5?
andy
"Have I just found the ultimate minimalist mod?? straight off the DAC with a filter - no op amps, tubes etc??"
Internal dac filter?
now back to work
allan
got the pdf with the pcb layout
awesome! thank you very much
something to investigate while i'm waiting for the tent clock.
rowemeister
HF signal - Data Signals, how about cat5?
andy
"Have I just found the ultimate minimalist mod?? straight off the DAC with a filter - no op amps, tubes etc??"
Internal dac filter?
now back to work
allan
rowemeister said:
Cat5(e) is network cable. (e) i think
supposed to be designed for insulated 100Mhz+ data transfer
at the frequency we need should not pickup to much noise
cleaner data transfer?
a couple of posts somewhere in the diy forum were looking at it
don't remember the outcome or where i saw it.
I see if i can find it.
allan
just did search
lots of ref to cat5e
some were using for interconnect cable
will try to narrow it down
rowemeister said:sweet nice one
I was looking for info on i2s data transfer and the cat5 seemed like the easiest idea.
bit more data
http://www.diyaudio.com/forums/showthread.php?s=&postid=166115&highlight=#post166115
jocko's in good form
allan
