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 17 Jun 2018, 17:21

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2, 3  Next
Author Message
PostPosted: 02 Apr 2009, 11:40 
Offline

Joined: 30 Mar 2009, 00:56
Posts: 8
Location: Western Australia
Hi all.

I just finished off my first amp build (I have made a few guitar effects previously) and thought I'd show it off :D ... Its a stock Cmoy except the power caps have been upped to 470's and I'm only using one 9v battery. The chip is a BB OPA2134PA. The enclosure is a Hammond 1455.

I had thought of etching a board for it but it seemed so suited to stripboard I didn't bother. Everything except the chip was bought locally, that I got from smallbearelec.com (where i buy my guitar effect parts). The two sockets with jumpers are for the optional output resistors.

Image

All wired up.

Image

A view from the rear. The battery lead is very short so the cable tie is to make it easy to remove it from the battery while in the enclosure, it also serves to hold the battery still when the cover is screwed on 8-)

Image

The finished amp. It works and sounds great and seems to have plenty of volume even with one battery. A slightly bigger enclosure would have been less fiddly as the in/out/pwr/vol panel is very snug but it does all fit... just

Image


Top
 Profile  
 
PostPosted: 02 Apr 2009, 17:02 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4551
Location: Winnipeg, CANADA
Hi Laika, that is a fantastic job! :up:

I like the sound from the OPA opamps and the price is reasonable. Would it be ok if I add the photos to the Photo Gallery on the site?

Cheers,
Gio

_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
PostPosted: 02 Apr 2009, 19:30 
Offline

Joined: 30 Mar 2009, 00:56
Posts: 8
Location: Western Australia
Thanks :) ... Yeah feel free add the pic's to the gallery, I know I like checking out other peoples projects.


Top
 Profile  
 
PostPosted: 02 Apr 2009, 21:37 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4551
Location: Winnipeg, CANADA
I just added it to the gallery.
Image

What did you think about the sound and what cans are you using with it?

Cheers

_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
PostPosted: 03 Apr 2009, 19:17 
Offline
Project Author
User avatar

Joined: 03 Aug 2008, 20:22
Posts: 386
Location: Denver, Colorado
Great job, very neat build. Which gain did you go with?


Top
 Profile  
 
PostPosted: 04 Apr 2009, 00:22 
Offline

Joined: 30 Mar 2009, 00:56
Posts: 8
Location: Western Australia
gmilitano wrote:
What did you think about the sound and what cans are you using with it?

Sound is better then I expected, very transparent... nice! I've got a pair of tired Beyerdynamic DT411 that I'm about to replace with some Grado SR80i's
roggom wrote:
Great job, very neat build. Which gain did you go with?

11 according to info on the headwise site were I worked from.

Since I start work on this amp I found a local source of the 2134 op-amps and these smaller pots that would make the panel less cramped.
Image

I'm feeling inspired to get started on a Gainclone now :)


Top
 Profile  
 
PostPosted: 04 Apr 2009, 09:33 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4551
Location: Winnipeg, CANADA
Laika wrote:
I've got a pair of tired Beyerdynamic DT411 that I'm about to replace with some Grado SR80i's

Hi Laika, I have a pair of Grado SR80 headphones. I liked the midrange over that of the SR60, but the SR60 had better low end. See the attached Grado Headphone frequency measurements (measured by headphone.com)
Attachment:
Grado-SR60-SR80-SR125-Headphone-Frequency-Response-Plot.png

Also, depending on what you are using as a source, you may want to try a lower gain.
Cheers,
Gio


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


_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
PostPosted: 05 Apr 2009, 05:50 
Offline

Joined: 30 Mar 2009, 00:56
Posts: 8
Location: Western Australia
gmilitano wrote:
Hi Laika, I have a pair of Grado SR80 headphones. I liked the midrange over that of the SR60, but the SR60 had better low end.

Interesting .. I thought the 80's were said to have better bottom end than the 60's (just from reading comments on the web)... maybe Its a good thing I haven't ordered my new headphones just yet.... I might look at getting the 60's instead.
gmilitano wrote:
Also, depending on what you are using as a source, you may want to try a lower gain.

Yeah I had some time over the weekend to try all my various sources and the gain was a bit much so I added sockets for the gain resistors and tried a few different values. For now I've changed the gain to ~ 6x instead of 11x and this seems more useful... I will have to see how this works out when I get my new cans.


Top
 Profile  
 
PostPosted: 05 Apr 2009, 10:10 
Offline
Editor
User avatar

Joined: 28 May 2008, 21:53
Posts: 4551
Location: Winnipeg, CANADA
Hi Laika, I found that the SR60 are not as smooth as the other models in the midrange and the highend. I'm not sure how the new SR60i and SR80i are different.

If you don't need the gain, my preference was to use lower and I settled on about 4 to 6.

_________________
[ DIY Mains AC Power Cable Cord ] - [ Gobo LM1875 Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]


Top
 Profile  
 
PostPosted: 05 Apr 2009, 17:55 
Offline
Project Author
User avatar

Joined: 14 Oct 2008, 17:35
Posts: 901
Location: Dartmouth, Nova Scotia
Nice headphone amplifier, I like how compact it is. I made one of about the same size, but does not work as well as yours and has no volume control, and not enough gain to be used for an MP3 player, which really defeats the point of it so at some point I will need to rework the circuit.

But it is the simplest amplifier on earth... only one little NPN transistor and a couple of resistors and capacitors. Just felt you may be interested in seeing it and maybe try the design for your self, all you need is a 2N3904, and it is so simple I don't even have a schematic for it. ;)
Attachment:
Mini headphone amp internals(small).jpg
Attachment:
Mini headphone amp(small).jpg

Ask me if you want to know more about the circuit...


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


_________________
My Mini 12AU7 Tube Preamp, Pioneer SX-D7000, JVC XL-V221BK, JBL L80T, DCM TF700


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2, 3  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 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