DIY Audio Projects Forum
 NEW  Matt presents bias and operation data for the 6V6 tube in SE operation - 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization.

DIY Audio Projects Forum

Welcome to the DIY Audio Projects Message Forum. Use these forums to discuss Hi-Fi audio and to share your DIY Audio Projects. Registration is free and required to post messages and view the file attachments. Registration will only take a minute and registered users do not see any advertisements. After you have completed the online registration process, check your email (including spam/junk folder) for the verification email to activate your account. New members are under moderation - so your posts will not be visible until approved by a moderator. See the Read Me 1st, Forum RULES and Forum FAQ to get started on the forum.

It is currently 20 Jan 2018, 11:58

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 23 posts ]  Go to page Previous  1, 2, 3  Next
Author Message
PostPosted: 19 Nov 2016, 03:05 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
These big speakers have been finally set free when driven by a set of 150W Class D Tripath monoblocks. They have never sounded so good. The amp sold today so I'll have to build one for me.

_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 20 Nov 2016, 00:32 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
Well the T3 sold but I have re-tubed my Black Lace 6V6 SE UL with some NOS Trigons and feeling the love. Due to the high efficiency of these big speakers a couple of watts will play awfully loud. Bottom end is not super deep (-3db 50Hz) but more than enough for the music I listen to.

_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 08 Mar 2017, 12:54 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
I have changed the Xovers on my Beyma 15" concentrics a few times. The ones I have been using for some time have a 2nd order roll on the woofer and a third order on the tweeter Xing at 1600hZ. I read recently (a number of times before) that Xovers reduce dynamics, immediacy and transparency. Probaly why some single full range drivers with no Xover sound so fast and transparent.

So once more I changed the Xovers on the Beymas. Now there is just a single 4.9uf cap on the tweeter and a 0.66mH DIY ferrite choke on the woofer for a Xover at 2K. The Beymas woofer goes to 4K but starts to roll at 2K. Good place to roll.

I picked up +3db of volume and great speed and dynamics straight out of the starting gate. Definitely far more lively and more forward. Will it stay this way, I'll let you know if I change it back
Attachment:
image.jpeg
Attachment:
image.jpeg


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.


_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 26 Mar 2017, 05:02 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
A friend (Steven) tested the big Beymas today. Near field measurements were a bit scary but move back to the listening position (3.5m) and things looked a lot better. Interestingly enough my listening note ps agreed with the tests. Has tests good down to 40hz.

One thing we we did find is the tweeter needed to be inverted where with a first order Xover it shouldn't need it. Inverting it really cleaned up quite a 5db bulge around 2K. We never would have guessed.

Also the concentric tweeter has no problems being flat to 20K and beyond. A small poly I put across the padding resistor to the tweeter gives a very slight lift in frequencies from 15K on giving about +2db at 20K. Almost like a built in super tweeter. All for $2! It works an absolute treat and easy to calculate for your system.

Steven was quite impressed with the speakers (he is a Pluto man). He really wasn't expecting them to sound as good as they did. He agreed too that there is little difference between my DIY 6L6 SE UL tube amp and DIY 150W Tripath class D. He thought both were excellent. The obvious difference is a bit more (only a bit more) bass with the Tripath amps. On some tracks it is very obvious on others it is barely detectable.

We we also proved there is no advantage with with the far more complex Xover. The 1st order is doing a great job with more output and greater dynamics. Just as my ears told me.

_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 26 Mar 2017, 18:05 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
Here are two graphs. One close mic woofer and rear port. The port is tuned to 50hz and covers rom 30 hz to 80hz.

The other at listening position. The green graph is with tweeter inverted. Easy to see the smoothing effect. All with 1ts order Xover. Note the treble extension past 20KhZ.
Attachment:
full system tweeter inverted green.jpg
Attachment:
port & bass close mic 1st oder.jpg


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.


_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 12 Jul 2017, 21:16 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
While playing Jagger's Primitive Cool up loud on my 2W amp I measured the db output. At 1mtr from the speaker 94dbA at my listening position 3m back 91dbA. These were peak readings.

No distortion and plenty of slam.

_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 20 Jul 2017, 20:39 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
A few months back I changed the Beyma Xovers to 1st order at 2KHz. Then changed it again to 1200Hz. I have used quality yellow Metalised poly 100V caps in the past put changed the 4uf cap for a Russian Mil. PIO cap. I required 4.2uf so added a 220nF poly. I didn't expect much improvement in sound but the cap which was in there was slightly off value.

I got a huge shock. The midstreble just got so much clearer and cleaner and even more dynamic. I had to reminding myself of the small change. Also recently I added yet more snubbing caps to my latest 6L6 SE UL wine box power amp. I noticed then the amp got a lot quieter and now with the Xover refinement I feel the system is running at 100%. No joke. Really happy and the total two upgrades probaly cost less then $20!

_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 26 Nov 2017, 19:25 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
After experimenting with different Xover points; 2000hZ and 1600hZ I finally settled on 1100hZ. Also back to a 1st order Xover from 3rd on the tweeter to 2nd on the woofer and other variations.

1st order gave the most dynamic sound and combined with a ferrite based 1.16mH choke and PIO Russian Military caps greater dynamics all over. The treble sounded clearer and sharper with the PIO cap over even expensive dedicated Poly caps. To get the 4.5uf required I used a 4uf and 0.47uf PIO cap. Cat5 twisted pairs bring it all together.
Attachment:
PB263661 (800x600).jpg


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.


_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
PostPosted: 27 Nov 2017, 03:48 
Offline

Joined: 14 Jul 2015, 03:30
Posts: 2
Hi from Spain:

mwhouston wrote:
...1st order gave the most dynamic sound and combined with a ferrite based 1.16mH choke and


Maybe you can try my cheap tweak with my KEF Q100 speakers. Würth 150 kHz ferrite in woofer cables.

[Spanish] http://aficionados.foroactivo.com/t342- ... ass-reflex

Image

and the little 10nF styroflex bypass with capacitor tweeter.


Top
 Profile  
 
PostPosted: 27 Nov 2017, 16:25 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 4799
Location: Australia
How do you think the 10nF cap helps?

_________________
Projects: "Sanctum" - 12AU7 and 6AS7 direct coupled headphone amp | "retro-Oatley 6J6" - 6J6 push-pull headphone amp with OPTs | "Mimic Carbon" - carbon resistors and PIO caps. MM phono preamp
Website: retro-thermionic


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 23 posts ]  Go to page Previous  1, 2, 3  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: Bing [Bot] and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
DIY Tube Projects :: DIY Tube Amp Kits :: DIY Speaker Projects :: DIY Solid State Projects :: DIY IC / Op-amp Projects :: DIY Phono Projects :: DIY Cable Projects :: Hi-Fi Audio Schematics
© diyAudioProjects.com - Terms of Service - Privacy Policy