Go Back   Home > Forums > > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 14th September 2019, 01:05 PM   #1
Neville is offline Neville  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Georgia
Default Embarking on my SSE journey

Just put an order in for SSE pcb. Was thinking of running this in triode mode\EL34 for my Zu Audio - Omen Dirty Weekend mk2 speakers which are 97db. Sounds rather naughty doesn't it - perhaps the manuf could have chosen a better name or its great marketing?

I would like to hear any advice on your build experience. Does the build benefit from boutique parts ? What has been your experience with tube rolling? I have a lot of tubes in my stash but no el34 and 12at7's so any advice would be appreciated.

if you have any iron or parts lying around that I could purchase off you please let me know via pm.

Thx
Neville
  Reply With Quote
Old 18th September 2019, 05:15 PM   #2
juststeve is offline juststeve  United Kingdom
diyAudio Member
 
Join Date: Jan 2017
Location: Norfolk, UK
I built it as per the parts list. Had it running for a couple of months powering headphones,Hifiman HE6.
First I changed the coupling caps to Vcaps, big differance, better imaging and bass.
Few weeks latter changed all resistors to Audio Note no change I could detect.
Added a Khozmo Stereo Series Stepped Attenuator, 48 step found it to be a gain in imaging and highs. But not huge.
Tube rolling I change from 12at7 Mullard to Siemens alot. Siemen is better at vocals than Mullard which then is better at rock.
Changed the rectifier valve from Harmon to Gold Lion apart from the Vcaps this was poss the biggest change in sound for the better.
I built it with Edcor CXSE25-8-5K running KT88, Gold Lion reissue. As per the basic build layout.
This is my end game amp and I love how it sounds and don't think I could better it at my buget.
  Reply With Quote
Old 19th September 2019, 12:36 AM   #3
Yukon888 is offline Yukon888  United States
diyAudio Member
 
Join Date: Oct 2012
Location: Rochester, NY
The output tubes that I've tried are Mullard EL34 reissue and Gold Lion KT88 reissue. The EL34 have a slight sq advantage in the midrange and are slightly more forward in the mids. However, I find them lacking in bass. To my ears, the GL KT88 really don't give up much in the mids compared to the EL34's but also have much better bass. Using them with the big Edcor CXE opts, I'm getting solid, articulate bass that rivals that of a good solid state amp. The soundstage is wide and 3d.

The preamp tubes that I've tried are Amperex Bugle Boy 12at7, Mullard CV4024, Tungsram 12at7, and GE five star 6201. My favorite here is the Bugle Boy, with the Mullard a close second.

Speakers are Klipsch Forte II, which are 99db efficient.

As always, your ears and mileage will vary.

Check out post #73 by "rknize" here:
Tubelab Simple SE with big honkin' Edcors?

Good luck with your build!
  Reply With Quote
Old 19th September 2019, 08:45 PM   #4
Neville is offline Neville  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Georgia
Wow thank you both juststeve and Yukon888 for your input. Over the years I have accumulated a huge stash of 6550,KT88 and all the various input tubes but none I can use for this project so your feedback will certainly help.

I been thinking about getting all my iron from Edcor and I believe they ask you what impedance for the OPT - my Zu Audio's are 12ohms but I want to be able to use 4 and 8 ohm if possible. Will 8 ohms have any adverse affects? What do you recommend?

I was thinking of the XPWR035 and CXSE25-8-5K but Edcors site only refers me to the CXSE25-5K. Assuming this new part is just with the drop down option of whichever ohms you want?


Thx

Last edited by Neville; 19th September 2019 at 09:08 PM.
  Reply With Quote
Old 19th September 2019, 09:33 PM   #5
Yukon888 is offline Yukon888  United States
diyAudio Member
 
Join Date: Oct 2012
Location: Rochester, NY
Quote:
Originally Posted by Neville View Post

I was thinking of the XPWR035 and CXSE25-8-5K but Edcors site only refers me to the CXSE25-5K. Assuming this new part is just with the drop down option of whichever ohms you want?


Thx
Yes, the drop down menu lets you chose the secondary impedance.
  Reply With Quote
Old 19th September 2019, 09:36 PM   #6
Yukon888 is offline Yukon888  United States
diyAudio Member
 
Join Date: Oct 2012
Location: Rochester, NY
Quote:
Originally Posted by Neville View Post

I been thinking about getting all my iron from Edcor and I believe they ask you what impedance for the OPT - my Zu Audio's are 12ohms but I want to be able to use 4 and 8 ohm if possible. Will 8 ohms have any adverse affects? What do you recommend?



Thx
I'm not knowledgeable enough to give you a firm answer on this, so hopefully someone else will chime in.
  Reply With Quote
Old 20th September 2019, 05:42 AM   #7
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Embarking on my SSE journey
Neville,

You can check out the One Electron UBT-2 - available off the shelf and has multiple secondary taps (4, 8, 16 Ohms).

With the Edcor transformers it looks like you can select one secondary impedance only.
  Reply With Quote
Old 21st September 2019, 12:57 AM   #8
Neville is offline Neville  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Georgia
Thanks zman01 for that recommendation. After searching I don't see anybody using this model so kinda on the fence about this. I really want a true and tested one. I know that from Decware forums they have 12/16ohms speakers connected to the 8ohm tap and I see this on other manufacturers amps too. So I am thinking that driving 120hms from one of the Edcor 8ohms shoudn't be a problem - can somebody confirm this?

btw I can't wait to get this ordered, built and compare it to my Decware amp.

thx
  Reply With Quote
Old 21st September 2019, 03:06 AM   #9
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Embarking on my SSE journey
Neville,

Found this:

One Electron transformer good or bad?

You can drive a 12 ohms speaker from the 8 ohms tap. The tube will see a different load though. To simplify, if the speaker impedance is around 12 ohms throughout the frequency range, and if it is connected to the 8 ohms tap of a 5k OPT, the tube will see 7.5k load. (12 is 1.5 times of 8, and 1.5 x 5k= 7.5k).

For a speaker with nominal 4 Ohm spec, connected to the 8 Ohm tap of a 5k OPT, the tube will see a 2.5k load (4 is 0.5 times of 8, and 0.5 x 5k= 2.5k).
  Reply With Quote
Old 21st September 2019, 04:10 AM   #10
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Embarking on my SSE journey
Just to add, if you notice in my previous post I mentioned "to simplify", as speakers in real life uses cases usually do not have a flat impedance curve throughout the frequency range, rather they can go up and down a bit; however "flattish" throughout the majority of the curve is easier for the amp.

Now, if I were asked to choose a spec for the Edcor CXSE25 transformer with KT88/6550 tubes and to be using with your speakers, I would have been more partial towards a 3.0K or 3.5K transformer with 8 ohms tap.

You can check out the simulations provided by George (Tubelab) here:

Tubes and Applications | Tubelab

What power transformer are you planning to use?

Last edited by zman01; 21st September 2019 at 04:18 AM.
  Reply With Quote

Reply


Embarking on my SSE journeyHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
my journey mfitzgibbon Full Range 8 10th November 2017 04:45 PM
Embarking on my first DIY speaker Project - Advice please Ken98 Multi-Way 6 6th June 2017 06:00 PM
My new Journey N7XG Chipamp 10 12th February 2010 06:56 PM
X-LP Mod Journey pjpoes Analogue Source 2 11th March 2007 07:35 AM
Embarking On A Gainclone 5.1 Channels Alphas Chip Amps 10 20th June 2005 02:26 PM


New To Site? Need Help?

All times are GMT. The time now is 04:45 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki