Need help evaluating 2A3 transformer coupled designs - Page 3

Andrewbee · 12th October 2003, 05:23 AM

I could not get the pics under 100K so made a quick Mac Homepage. I think you will have success now (If I can remember the addy correctly) If the link does not work I have it below.
Its Waaaaayyy past my bedtime.
Nite nite

http://homepage.mac.com/andrewbee/FileSharing3.html pics here

Eric · 15th October 2003, 06:40 PM

Thanks for the pix, Andrew - quite an impressive array of DIY! My collection is growing, but very slowly...

Andrewbee · 16th October 2003, 01:10 AM

thanks. Unfortunately I have quite a bit more and am now needing to sell some of it to make space. it is a learning experience though.

My problem is i spend more time making stuff than listening to it. I dont drink, smoke or carouse so this is my vice.
I have all my toys at home so I don't need to go anywhere to have fun.

Andrew

Bas Horneman · 16th October 2003, 03:06 PM

Quote:

Long answer is the gainclone is better overall from lows to highs.

Hi Andrew,

Long time no speak..

Cheers,
Bas

EC8010 · 16th October 2003, 03:33 PM

You do need 1000uF rather than 100uF, otherwise the anode resistance of the 417A will rise at low frequencies, and cause bass loss due to the finite primary inductance of the inter-stage transformer. The high transconductance oif the 417A coupled to that low value cathode bias resistor means that you need a large capacitor.

G · 16th October 2003, 04:09 PM

Thanks for the explanation about the 1000uF cap. I've never built a amp using a interstage transformer and so was unaware of this problem and solution.

G

Andrewbee · 16th October 2003, 05:52 PM

Hi Bas!
I thought I was busy but I think you have been busier

EC8010. Yup. I used Nichicon Muse's, 1000uF on the 5842 and 100uF on the 2A3.

It is time to rebuild it but I have two projects inline, D-57 cabinets
for my 208 Sigma's and a 12B4 preamp as well.
I start expanding my house next week so will have more space to keep my ever expanding mound of diy stuff

Andrew

Bas Horneman · 17th October 2003, 03:39 PM

Quote:

I thought I was busy but I think you have been busier

Most stuff is still in progress though...:-)

By the way ...your tube amp chassis look great!!!

Cheers,
Bas

12th October 2003, 05:23 AM	#21
Andrewbee diyAudio Member Join Date: Apr 2002 Location: Cayman Islands	Pics at last I could not get the pics under 100K so made a quick Mac Homepage. I think you will have success now (If I can remember the addy correctly) If the link does not work I have it below. Its Waaaaayyy past my bedtime. Nite nite http://homepage.mac.com/andrewbee/FileSharing3.html pics here

16th October 2003, 03:33 PM	#25
EC8010 diyAudio Moderator Emeritus Join Date: Jan 2003 Location: Near London. UK	That cathode bypass capacitor... You do need 1000uF rather than 100uF, otherwise the anode resistance of the 417A will rise at low frequencies, and cause bass loss due to the finite primary inductance of the inter-stage transformer. The high transconductance oif the 417A coupled to that low value cathode bias resistor means that you need a large capacitor. __________________ The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...

16th October 2003, 04:09 PM	#26
G diyAudio Member Join Date: Apr 2002 Location: Belleville, IL.	Thanks for the explanation about the 1000uF cap. I've never built a amp using a interstage transformer and so was unaware of this problem and solution. G __________________ Gavin

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
6sn7 direct coupled and transformer coupled	neazoi	Tubes / Valves	3	23rd May 2008 03:30 PM
6922 transformer coupled	Andersen	Tubes / Valves	12	9th April 2008 02:47 AM
Transformer Coupled Linestage	hpn5350	Tubes / Valves	11	27th February 2008 02:11 PM
transformer coupled amplifiers	latala	Solid State	11	27th February 2006 03:26 PM
Transformer coupled linestage	Panelhead	Solid State	10	18th October 2005 09:57 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

15th October 2003, 06:40 PM	#22
Eric diyAudio Member Join Date: Nov 2000 Location: Central PA, USA	Thanks for the pix, Andrew - quite an impressive array of DIY! My collection is growing, but very slowly...

16th October 2003, 01:10 AM	#23
Andrewbee diyAudio Member Join Date: Apr 2002 Location: Cayman Islands	thanks. Unfortunately I have quite a bit more and am now needing to sell some of it to make space. it is a learning experience though. My problem is i spend more time making stuff than listening to it. I dont drink, smoke or carouse so this is my vice. I have all my toys at home so I don't need to go anywhere to have fun. Andrew

16th October 2003, 05:52 PM	#27
Andrewbee diyAudio Member Join Date: Apr 2002 Location: Cayman Islands	Hi Bas! I thought I was busy but I think you have been busier EC8010. Yup. I used Nichicon Muse's, 1000uF on the 5842 and 100uF on the 2A3. It is time to rebuild it but I have two projects inline, D-57 cabinets for my 208 Sigma's and a 12B4 preamp as well. I start expanding my house next week so will have more space to keep my ever expanding mound of diy stuff Andrew

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read