DIY Audio Projects Forum
http://diyaudioprojects.com/Forum/

NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread
http://diyaudioprojects.com/Forum/viewtopic.php?f=10&t=1799
Page 60 of 170

Author:  koogar [ 24 Jan 2011, 07:01 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

next667 wrote:
uups sorry for double post, but will irf540 IR do? or irf 640/630?
i've checked data sheet for irf540, it just seems that current is a bit higher...
otherwise recommend a sonically superiour transistor :)

Quoted from Rogers project page
Quote:
"Q1 - The MOSFET (Q1) can be replaced by an IRF610, IRF611 or IRF612, all of which will work as well. Stay away from IRF530 or IRF540 types (commonly found in power supplies) as there will be terrible roll-off of the highs. "

Koogar

Author:  ferdinandkeil [ 24 Jan 2011, 13:13 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

I've cleaned up my schematic and attached it in Cadsoft Eagle format.
It's a single sided board and should be fairly easy to do at home. Mine was done professionally as I'm put off by the chemicals required.

- Ferdinand

Author:  next667 [ 25 Jan 2011, 04:30 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

ahh thanks :) i somehow missed it...so i'm off to search for a fet :)

Author:  Gio [ 25 Jan 2011, 13:19 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

Hi Guys,

Sorry for not keeping up with changes to the project page. I knew about the silk screen and I forgot to address that in the last update. I will update the page shortly to reflect that change.

Also, there have been a number of excellent builds by others - great work guys and keep it up! This project has really taken off and in a short time is the most popular one on the site. Better yet is that a lot of the builders are brand new to the hobby. Kudos to Rogers for sharing this project.

So that new information is all contained in one place I was thinking of adding a second page to the project which will include photos of some of the many excellent builds, the point-to-point wiring diagram by porkchop to help those who want to build in that manner, and for the PCB makers the layouts by Koogar and ferdinandkeil. I will contact everyone individually to make sure that is ok. If anyone has any comments or suggestions please feel free to comment or send me an message (email is in the site banner at the top).

Cheers

Author:  Rohan [ 27 Jan 2011, 11:29 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

i actually tested out with IRF630 and they seriously do have extremely hi-roll of's for upper frequencies DO NOT USE THEM!

Author:  nat [ 27 Jan 2011, 15:18 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

Guys, been a while. Have been listening to mine for a while now, it's a nice simple project. Much to be admired in the KISS principle. Here's the rub:- been doing lots of reading and would REALLY like to try it on 24v (more linear region). I'd like to know what changes i'd need to make. If i'm thinking correctly, the htr stays on 12v and there'd be resistor changes for loading , and 317 . Caps on mine unfortunately aswell 16v !! Anyone tried this yet ? Being lazy i spose asking but, if ya don't ask.........i'm also reasonably sure that at least some of you want/have tried it. Roggom please forgive but i've read all 60 pages just to make sure i'm not asking a pre-asked question here. I'm, hoping it's worth the teardown?

Author:  krayz605 [ 30 Jan 2011, 03:34 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

Hi everyone. This was my first audio project. It was a lot of fun and a good learning experience. Thanks for all of the information.

Here are a few pictures. The enclosure is temporary. I am a prototype developer and I am going to tig up a nice enclosure when I get the time. Sorry for the cell phone pics.
Attachment:
0128112040.jpg
Attachment:
0130110202.jpg
Attachment:
0130110201.jpg

Author:  rasty [ 31 Jan 2011, 14:18 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

Greetings!
I am currently building this amp, but I have a question about C1. I have couple of great film caps, but they are little far away for 2,2 uF. The closest I have is 0,37 uF and the next closer is 33 uF. Can I get away with using such values?

Author:  nat [ 02 Feb 2011, 08:09 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

Hiya, seems this thread is all but dead now!!?? My personal take is:- C1 is there to block dc from source component mainly, it may act as a filter also. If a portable (discman/md/dat or whatever) is being used AND you're feeding amp from headphone skt on that device, it's not a critical component bar the fact that bass may well suffer? Of course IF the source has a 'fit' and decides to give out dc, there may be problems but, C3 should block, in that eventuality. Shoot me down in flames if i'm wrong but i believe i'm thereabouts :confused: . From experience (cos i had them!) DON'T use irf630, it's a killer soundwise :mad: . As long as gate capacitance is roundabout 510 figure, it won't be a problem. It's all dealt with previously. Just one more thing, i had, along with quite a few others, a problem with setting bias. It turned out to be a bad NEW tube. I would advise fitting the pots instead of fixed resistor to allow for both this and, setting equal bias for both channels. Do try a xfeed if closed back /in ear phones aswell, it all adds to the experience and costs virtually nowt. Cheers

Author:  Gio [ 02 Feb 2011, 13:27 ]
Post subject:  Re: NP-100v12 - 12AU7 / IRF510 HeadAmp Support Thread

nat wrote:
would REALLY like to try it on 24v (more linear region). I'd like to know what changes i'd need to make. If i'm thinking correctly, the htr stays on 12v and there'd be resistor changes for loading , and 317 . Caps on mine unfortunately aswell 16v !!

There are a couple ways you could do this, primarily dependent on the supply you will be using. You could leave everything as is at 12V and apply 24 volts to the B+ for the tube. Yes, the heaters would have to remain at 12V. You could also look at lifting the voltage on the mosfet. I like the sound better at closer to 20V but have not tried 24V, which should be fine. If you increase the voltage on the mosfet you will need to heatsink. At the time you may also wish to adjust current in the CCS to find a point that sounds best.
Cheers

Page 60 of 170 All times are UTC - 6 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/