Wow, sounds like this would take more technical know-how & time than I have. Ermm... Perhaps it'll be better if I went commercial.
Thanks anyway Dave.
Search found 16 matches
- Mon Jun 26, 2006 12:03 am
- Forum: Inductors
- Topic: Choke for RIAA
- Replies: 8
- Views: 13291
- Sat Jun 24, 2006 3:13 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
I think you owe it to yourself to give it a try. Above you mentioned that you were using a .04 gap for the 1:1's by this do you mean a .04 gap which is a .02 spacer (yellow). Since each core requires two spacers they add so two yellows gives you a .04 gap as read on the L vs. I plots. Hmm... Ok. Wi...
- Sat Jun 24, 2006 2:00 am
- Forum: Inductors
- Topic: Choke for RIAA
- Replies: 8
- Views: 13291
Oh crap! I was hoping that you would've and that you could easily whip up a set. I'm willing to try something out, but I'm a total novice when it comes to RIAA compensation (How it works, what to listen for etc.), so the chances of me running around in circles is pretty high. I have personally never...
- Sat Jun 24, 2006 1:42 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
Hey Ken, thanks for the input. did you ever try the Large 1:1 as a plate choke and cap couple to the output (parafeed)? I did try the 1:1 briefly as a choke., but then switched to a true 1:1 configuration, liked it immediately and never went back. :oops: I do remember that the low mid and mid mids w...
- Fri Jun 23, 2006 2:33 pm
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
I'm sorry; this has taken so long and also because I only managed to do the very minimal amount of bread boarding. I was hoping to do more in the future, but this has taken too long already and I'm not sure when I'll be able to get to it again. Here are the observed results. Small lam OPT with large...
- Thu Jun 22, 2006 3:03 pm
- Forum: Inductors
- Topic: Choke for RIAA
- Replies: 8
- Views: 13291
Choke for RIAA
I've seen some circuits that use a choke and cap/resistor combo for RIAA ccompensation. What are the benefits to having the choke there? Indeed, whey even the need for one? I've seen similar circuits without the choke.
- Sun Jan 22, 2006 5:31 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
- Fri Dec 16, 2005 1:44 pm
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
- Wed Nov 16, 2005 6:45 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
- Fri Oct 07, 2005 8:54 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
- Tue Sep 20, 2005 1:24 pm
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
- Tue Sep 20, 2005 5:33 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
I can do that, but you might want to consider slipping some nickel in for the first 1:1 to mix it up a bit. So we are talking a nickel/amorphous mix? For the cathode feedback, how many dB are we talking about? Something small, say 5-8db? I could do up the following to give you a bunch of options to...
- Mon Sep 19, 2005 6:02 pm
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
- Mon Sep 19, 2005 4:58 pm
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
You connect the tube's filament curcuit through a dedicated winding in the secondary to give you feedback. Generally accepted as a better option than running the feedback from one of the speaker output taps. DA30 looks vaguely 300B-ish in terms of characteristics (apart from lower plate dissipation)...
- Mon Sep 19, 2005 4:12 pm
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
Ken has never designed an amp from scratch so lets encourage him over to the dark side. I'm not a total novice, but I tend to throw stuff together without any testing and just solving the problems as they occur. In looking at the curves, I'd look at operating the tube at ~325V 70ma with -80V bias. ...
- Sun Sep 18, 2005 9:35 am
- Forum: Transformers
- Topic: DA30 Amplifier
- Replies: 24
- Views: 28133
DA30 Amplifier
Contacted Dave via email for some ideas a couple of days ago and now will transfer the discussions here. The DA30 tube Also called the PX25A which is a low mu (3.5) version of the PX25 (8 ish). At 500v on the anode it can provide 11w (A bit optimistic I think) of audio power from a 5-6k output trans...