BF862 based SE Class A Headamp without the HEAT - Page 42 - diyAudio
Go Back   Home > Forums > Amplifiers > Headphone Systems
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Headphone Systems Everything to do with Headphones

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th April 2017, 12:37 PM   #411
diyAudio Member
 
Join Date: Jun 2006
Location: Darmstadt
http://cds.linear.com/docs/en/datasheet/3042fa.pdf According to Figures G43/G50 PSRR and noise are getting better with lower current (down to 1 mA).

p.s.: For maximum performance - stability and low noise - you should be careful with C_set both low ESR and low ESL is required.

edit: the "cover" graph TA01b of the datasheet is a bit missleading saying that psrr up to 120db can be achieved with 200mA (G43 vs TA01b Cset 0,47uF vs 4,7uF other parameters are the same).
Attached Images
File Type: png 3042-G43.png (48.8 KB, 470 views)
File Type: png 3042-G50.png (60.0 KB, 473 views)
File Type: png 3042-TA01b.png (32.9 KB, 463 views)

Last edited by WatrixReloader; 24th April 2017 at 12:45 PM.
  Reply With Quote
Old 29th April 2017, 04:48 AM   #412
diyAudio Member
 
Join Date: Jan 2017
Location: Western NC
A few posts back I joked about being goofy and stacking SMT caps on top of each other, and soldering on leads. Turns out this is a real thing...recommended by Murata, in fact! They say you can stack up to five of them. This opens up some options...It'd be possible to create a 5x1uF C0G cap to fit in the narrow space for C1 on the PCA. Or even better, a 2x1uF PPS.
Click the image to open in full size.
A high capacitance monolithic ceramic capacitor | Leaded Products | Murata Manufacturing Co., Ltd.
Attached Images
File Type: png Screen shot 2017-04-29 at 12.23.03 AM.png (136.9 KB, 843 views)
  Reply With Quote
Old 29th April 2017, 05:08 AM   #413
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
I have these tiny 10uF 50v MLCC caps with leads. I used to use them for input coupling and would bypass with a 1uF film. But now I worry that they may have high distortion since not C0G. Probably X7R so I use them for power filtering only. They look like stacked SMTs. Tiny little packages dipped in epoxy.
  Reply With Quote
Old 4th June 2017, 11:59 PM   #414
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
I tried an amp with 10uF Silmic on input with 1uF MKS Wima film as a bypass. On output using 1000uF oscon with 100uF Silmic as the bypass. Observing the 10% rule of thumb. I don't know. Sound a great though.
  Reply With Quote
Old 5th June 2017, 09:42 AM   #415
kees52 is offline kees52  Netherlands
diyAudio Member
 
Join Date: May 2009
Location: Sprang-capelle Holland.
With capacitive outputs I did always use 1 nF 100 nF over the real big electrolite output cap, however for input the same, the hybrid of mine has 1 nF and 100pF parallel over 470 nF input cap. better audio pass through, or maybe a hoax, but I did hear the difference, tighter and faster,
  Reply With Quote
Old 17th June 2017, 08:12 PM   #416
JPS64 is offline JPS64  Germany
diyAudio Member
 
Join Date: May 2011
PCB ordered: 10F ELNA SILMIC SMD on input; 4x 220F OSCON + 022/MKP2 + tbd FKP2 on output; TKD potentiometer; NiMH/NiCd charging electronic.

Preparing 3D Printing datas for enclosure online ordering...

JP
Attached Images
File Type: png ONLY-PBA_ISO.png (719.9 KB, 41 views)
File Type: png COMPLETE-WITHOUT_CASE.png (505.4 KB, 42 views)
File Type: png COMPLETE-WITHOUT_COVER.png (463.1 KB, 36 views)
File Type: png COMPLETE-ISO.png (438.3 KB, 30 views)
File Type: png COMPLETE-BOT.png (278.0 KB, 25 views)
File Type: png COMPLETE-TOP.png (270.8 KB, 22 views)
File Type: png COMPLETE-FRONT.png (422.2 KB, 26 views)
File Type: png COMPLETE-DIM.png (273.4 KB, 30 views)
  Reply With Quote
Old 17th June 2017, 09:12 PM   #417
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
JPS64. That amp looks very nice. Is that a stack of PCB with bias used as a heatsink extended "fin"?

Check out the Silicon Harmony (6w into 8ohm single ended):



Click the image to open in full size.Click the image to open in full size.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio

Last edited by xrk971; 17th June 2017 at 09:15 PM.
  Reply With Quote
Old 19th June 2017, 10:48 AM   #418
diyAudio Member
 
diyRookie's Avatar
 
Join Date: Jan 2016
Location: Johannesburg
Well done X! What a beautiful beast. I can only dream of building something like this one day.

Looking forward to reading all the reviews, and I hope the orders start streaming in.
  Reply With Quote
Old 19th June 2017, 04:49 PM   #419
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Thanks DIYRookie. It is indeed a beast: hot and heavy to hold when fully warmed up.

But the sound is glorious.

Slight correction. Measuremts show max power is 5w into 8ohms before clipping.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio

Last edited by xrk971; 19th June 2017 at 04:52 PM.
  Reply With Quote
Old 22nd June 2017, 03:20 PM   #420
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Tidy wiring with SMPS moved inside.

Click the image to open in full size.
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Universal buffer/headamp based on OPA1622 OlegSh Headphone Systems 237 Yesterday 11:45 AM
LME498xx Based Headamp panson_hk Chip Amps 20 9th April 2013 10:20 PM
GB: BF862 Based Preamp npapp Group Buys 68 3rd February 2013 10:39 AM
SE Class A 200W PURE Heat lineup Solid State 28 25th November 2008 07:08 PM
Another Class A headamp idea Dxvideo Solid State 3 19th November 2007 08:08 AM


New To Site? Need Help?

All times are GMT. The time now is 03:15 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki