Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › How good is DIY audio compared to what you can get in the stores?
New Posts  All Forums:Forum Nav:

How good is DIY audio compared to what you can get in the stores? - Page 8

post #106 of 119
1/28/10 at 3:16am
Quote:
Originally Posted by Parafeed View Post
But the market will accept using the 307A, as a triode strapped pentode, out of production for years and hardly plentiful, both in terms of availability and tube rolling options?
i'm part of the market, and I could certainly never buy a 307A-based amplifier. I want more and cheaper options!
Reply
post #107 of 119
1/28/10 at 3:24am
[deleted]
Reply
post #108 of 119
1/28/10 at 3:35am
Quote:
Originally Posted by Parafeed View Post
So you order the BA with PX4's.....
PX4's are still made - though cheap they are not!

fortunately, with the flip of a switch and the twist of a dial, I can use 300b's
Reply
post #109 of 119
1/28/10 at 4:11am
Quote:
Originally Posted by nikongod View Post
Asking regal if he had heard the BA in the other thread got an answer that I think would impress a politician. Actually no direct answer from the scope jockey pushing numbers.Link to other thread, seep page 2

Regal:
Have you personally heard the BA amplifier?
What the heck is a "scope jockey"? For one my favorite headphones are made by Grado, if I was concerned with numbers I would be listening to Senn's or something right?

Any way yes, I did a head to head and the BA was not as good with Grados, my friend who owns it loves it with his 600 ohm Beyers and I thought it was great with my Sextetts, but with Grados, no it wasn't worth $3500 compared to what one with a little brains can build DIY. Meaning take a SOHAII and make it HV with more bias, but thats another thread.
Reply
post #110 of 119
1/28/10 at 4:17am
Quote:
Originally Posted by dsavitsk View Post
Speakers that one drives with 300B amps are designed to be driven by amps that have a high Zout and thus a low damping factor. Regal is arguing that Grados are not like this, and that they are more like standard commercial speakers that pair well with solid state amps. I think he is wrong, but those are the terms of his argument for better or worse.


But what we are doing with SET + Grados appears to be almost an order of magnitude worse than the typical 300B SET + high efficiency speaker enthusiast as far as damping factor is concerned, or am I missing something?
Reply
post #111 of 119
1/28/10 at 5:12am
Quote:
Originally Posted by regal View Post
But what we are doing with SET + Grados appears to be almost an order of magnitude worse than the typical 300B SET + high efficiency speaker enthusiast as far as damping factor is concerned, or am I missing something?
I think you are missing something. My 300b amps use 3500:8 transformers. rp of the 300b is roughly 800 ohms, and DCR of the OPTs is ~1 ohm, so Zout is close to 3 ohms. Damping factor is 2.7. As I said, when I used the 4 ohm taps sound really suffered. With a solid state amp they are unlistenable. Speakers are Fostex something or another -- I don' remember off the top of my head.
Reply
post #112 of 119
1/28/10 at 5:18am
10-4, thanks
Reply
post #113 of 119
1/28/10 at 11:19am
[deleted]
Reply
post #114 of 119
1/29/10 at 1:27am
Quote:
Originally Posted by Parafeed View Post
How does that work? Do you have an adapter? The PX4 uses a B4 socket, not the UX4.
both the Sophia and KR tubes use a UX4 socket, fortunately
Reply
post #115 of 119
1/29/10 at 10:33am
[deleted]
Reply
post #116 of 119
1/29/10 at 10:51am
Parafeed, do more research, any series resistance with a dynamic driver changes the drivers frequency response and character. Your experiement really just shows that headphones sound best without a series resistor, as has been shown by the Millett Hybrid and Soha builders years ago.
http://www.head-fi.org/forums/f6/hea...0/#post5551379

I'm glad your thinking though, and the 10 damping figure is just an old time industry standard, 5 may be fine for Grados. The area just needs more exploration when spending $3500 on amps with a damping factor of 2-3 with our favorite headphones. The best test would be to build a 300B (or other) SET with a single 300B per channel vs one with 2 in Parrallel which would lower the output impedance.


Edit: Also looking at your schematic you are using a cathode follower? So your output impedance should be very low, but remember most including me don't like their sound. Just trying to help.
Reply
post #117 of 119
1/29/10 at 2:01pm
[deleted]
Reply
post #118 of 119
1/29/10 at 2:26pm
Reply
post #119 of 119
1/29/10 at 2:56pm
Resistance != Impedance

Added resistance in series to the output of an amp is not the same has having an amp with a high impedance. Really not sure what Parafeed is trying to accomplish in his experiment.

I also agree with MikeW
Reply
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › How good is DIY audio compared to what you can get in the stores?