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 07 Dec 2019, 14:13

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 524 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9 ... 53  Next
Author Message
PostPosted: 16 Oct 2010, 17:25 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 5151
Location: Australia
Matt has managed to give us some values of the passive components. The cathode by-pass caps I can get from work and I used low ESR electros.

The all important inter-stage caps I have had to order from parts connexion. Qian, the customer, has requested Audio Note Silver caps. I, in obedience to his command, ordered the Audio Note Silver and Mylar caps (0.1uf) last night. Only $US404.00 for the pair. I can build a whole amp for that!

https://www.partsconnexion.com/capacito ... ilver.html

Anyone had any experience with these caps? Any comments? Should we have gone for Tin?

_________________
Projects: "Precision" - 300W Class AB Holton power amp | "retro2308" - chip based headphone amp | ”Calibre 834” - tube phono MM preamp |


Top
 Profile  
 
PostPosted: 16 Oct 2010, 19:09 
Offline

Joined: 18 Jun 2010, 12:46
Posts: 284
Location: Northern VA
http://www.v-cap.com/reviews.php

Some of these folks above prefer V-Caps, I've also heard from several of my friends who can afford audio note silver caps, that the V-caps (TFTF) sound better. I'm more than please with my set, but have no direct comparison experience.


Top
 Profile  
 
PostPosted: 16 Oct 2010, 21:34 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 5151
Location: Australia
rock4016 wrote:
http://www.v-cap.com/reviews.php

Some of these folks above prefer V-Caps, I've also heard from several of my friends who can afford audio note silver caps, that the V-caps (TFTF) sound better. I'm more than please with my set, but have no direct comparison experience.

So you do have the Audio Notes - Silver?

_________________
Projects: "Precision" - 300W Class AB Holton power amp | "retro2308" - chip based headphone amp | ”Calibre 834” - tube phono MM preamp |


Top
 Profile  
 
PostPosted: 17 Oct 2010, 00:16 
Offline
User avatar

Joined: 28 Oct 2009, 02:34
Posts: 501
Location: Utrecht Nederland
Hi Mark,

I do! But I don't like 'em any better than my Russian KI40's, btw. Difference in sound, almost inaudible, difference in price, huge, hahaha.

All the best.

_________________
Greetings from Holland, Ben

My DIY Audio Projects:
- Single-Ended 12B4A tube amp with ECC802S driver
- DIY Push-Pull KT88 tube amp (OddWatt amp from scratch)
- 832 / GU32 tube push-pull amplifier project


Top
 Profile  
 
PostPosted: 17 Oct 2010, 05:15 
Offline
User avatar

Joined: 08 Aug 2009, 03:11
Posts: 2229
Location: Chilliwack, BC
Bennybuis wrote:
....Russian KI40's, btw. Difference in sound, almost inaudible, difference in price, huge....

I was about to say that when I saw your post.

What about plain ol' MKP polypropylene from WIMA, Vishay/BC Compnents or Epcos?

Panasonic also has great sounding ones... their ECW-F(L) is available through Digikey. Example:
http://search.digikey.com/scripts/DkSea ... ND&x=0&y=0

Cheers!

_________________
-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design


Top
 Profile  
 
PostPosted: 17 Oct 2010, 08:47 
Offline
Project Author
User avatar

Joined: 08 May 2009, 08:20
Posts: 918
Location: Duesseldorf, Germany
Hi all,

like Gregg mentioned before, I would also vote for the good and cheaper MKP caps.
Since i bought them the first time, I stick with my Mundorf, Audyn or Solen caps. They are really good - for a resonable price.
Even the Orange Drops work fine (they are a bit like the Panasonics and sound really sweet to me).

All this caps are a bit different in sound, but who can really hear and feel that difference? "Normal" listeners or customers imo not.
Someone must have very good ears to hear the sonic quality and the special sound of a very special capacitor..
If there exists any very special sound for xxx dollars... I hope they are also made by japanese virgins at full moon.
That would explain the price ;-).

A pretty much better way to get a good sounding amplifier is a damn good design (IMO), not an $$$ component.

A few months ago i found an interesting article from Gabi (Gabriel Bucataru from Sound GarageTales)
about capacitors and the noise if they are not connected right. Might be a better improvement instead of spending much $$$:
http://www.soundgaragetales.com/amp-building/outside-foil-capacitor

Have fun ;-).

_________________
Cheers,
Tom.

Some of my projects: TDA2050 Chip Amp, the LM3886 Gainclone Thread and the Szekeres Headamp Thread.


Top
 Profile  
 
PostPosted: 17 Oct 2010, 09:31 
Offline
Project Author
User avatar

Joined: 06 Jun 2008, 18:23
Posts: 5151
Location: Australia
Thanks for your comments. I have a customer who wants these caps and I get to listen to them with no money leaving my pocket. Who am I to argue?

I'm a Jensen copper.paper and oil fan. Not just that I bought a $1K's worth so I have to love them for a long time yet.

_________________
Projects: "Precision" - 300W Class AB Holton power amp | "retro2308" - chip based headphone amp | ”Calibre 834” - tube phono MM preamp |


Top
 Profile  
 
PostPosted: 17 Oct 2010, 11:53 
Offline
Project Author
User avatar

Joined: 06 Apr 2009, 10:08
Posts: 1596
Location: US Pacific Northwest
Quote:
A few months ago i found an interesting article from Gabi (Gabriel Bucataru from Sound GarageTales)
about capacitors and the noise if they are not connected right. Might be a better improvement instead of spending much $$$:
http://www.soundgaragetales.com/amp-bui ... -capacitor


Be careful what you take away from this article. He is correct in the effects for his test setup, but his conclusions are dependant on the capicator having one side at AC ground. When installed in this position, if you grip the cap and induce a hum signal in the outer layer there is a normal capicative reactance to the inner layer (i.e. the no-outer foil part of the cap). For an 0.1 µf cap this is about 26.5kΩ (1/(2*pi*60*0.1e-6)). If the outer foil end is at ac ground, then the induced signal will be greatly attenuated, if not it gets pumped directly into the amp.

However, if the capacitor is installed in a position where one end is NOT at AC ground, say as a coupling capicator, then the effective noise path impedance is dependant on the components around the cap as well. In this configuration, any noise attenuation seen from signal induced in the outer shell is only attenuated the same as any other 60Hz part of the signal.

The only place I see where this might be an issue is in a very low signal input stage where a capacitor is being used as part of an equalization network and has one side tied to ground. In the coupling role I just can't see this making any real difference.

Just one Engineer's opinion. :)

_________________
Matt
It's all about the Glass!
http://www.CascadeTubes.com
Cascade Tubes Blog


Top
 Profile  
 
PostPosted: 17 Oct 2010, 17:36 
Offline
Project Author
User avatar

Joined: 08 May 2009, 08:20
Posts: 918
Location: Duesseldorf, Germany
Hi Matt,

thanks for the kind reply and for the comment. This was a great explaination!
I also must say that your thread is great. All the work and all the calculations you have done
are great stuff for learning and also great to improve the tube builders knowledge of basic designing.
The basics are explained very well and i think that advanced builders also can learn a lot here.

I must admit that i didn't follow the thread from the beginning, but the more i read the more i keep in mind!
Man - you must be an old school professional engineer ;-).

Let me thank you for all the work and knowledge you have submitted and shared in this thread.
I wish we had more people who share their knowledge on the DIY-Forums.
There are many people out there who want to know howto. Just my :2c:.

Have fun ;-).

_________________
Cheers,
Tom.

Some of my projects: TDA2050 Chip Amp, the LM3886 Gainclone Thread and the Szekeres Headamp Thread.


Top
 Profile  
 
PostPosted: 18 Oct 2010, 23:22 
Offline
Project Author
User avatar

Joined: 06 Apr 2009, 10:08
Posts: 1596
Location: US Pacific Northwest
An interesting issue has arisen with the power supply.

The combination of the high DC voltage (454v) and the moderately high current (196mA), giving rise to an equivalent load of only 2.31kΩ, while using a vacuum tube rectifier (5U4) means that the effective Edc/Em is only about 0.74. This means that I need a transformer secondary voltage of 1226VCT. I can get a 700 series Hammond transformer with a 1250VCT, 200mA secondary (it's an 8 pound beast) but it has no filament windings. This means that I'm thinking about a dual secondary Hammond u-bracket transformer for the 300B DC heaters (to remain hidden inside the chassis) and an Edcor dedicated filament transformer (XPWR28) for the 5U4 and 6SN7 filaments.

It looks like the power supply itself is going to be more complicated then the rest of the amp. I'll get the details of the design decisions and the resultant schematics posted as soon as possible.

_________________
Matt
It's all about the Glass!
http://www.CascadeTubes.com
Cascade Tubes Blog


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 524 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9 ... 53  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 15 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