Go Back   Home > Forums > > >

XRK Audio Your source for high performance projects and DIY components: amplifiers, headphone amps, preamps, natural sounding speakers, power supplies, protection circuits, and more

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
Old 3rd October 2021, 01:17 AM   #261
poseidonsvoice is offline poseidonsvoice  United States
Poseidon's Voice
diyAudio Member
 
poseidonsvoice's Avatar
 
Join Date: Jul 2004
Location: NC
X,

Any reason (other than inadequate transformer secondary voltage) that you are not using single rail SLB’s in this build?

Best,
Anand.
__________________
NPXP
Science is not a democracy - Earl Geddes; DIYAudio is a journey not a destination!
  Reply With Quote
Old 3rd October 2021, 01:48 AM   #262
xrk971 is online now xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
This amp being a balanced topology has inherently great PSRR and 1mV ripple PSU is not needed. I like the SLB but I also like simplicity. The SLB was designed for 5A and 6A is just over the limit. I felt using two SLBs was just too much complexity as the amp has a lot of parts internally. I wanted to free you some room and reduce complexity.
__________________
XRKaudio Store // Manufacturer’s Forum
  Reply With Quote
Old 3rd October 2021, 06:46 AM   #263
Dibya is offline Dibya
diyAudio Member
 
Join Date: Apr 2018
Location: Inside your preamplifier
Hi X,



It sounds amazing , specially midrange and soud stage(Very Wide)
  Reply With Quote
Old 3rd October 2021, 03:34 PM   #264
xrk971 is online now xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
Well it’s playing mono but the iphone records in stereo (with separated mic’s) so probably hearing the room reflections / acoustics.
__________________
XRKaudio Store // Manufacturer’s Forum
  Reply With Quote
Old 5th October 2021, 03:00 AM   #265
xrk971 is online now xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
I have some pre-production samples coming my way for some final XO tweaks and adjustments. These speakers have the custom CNC waveguide for the tweeters, and a beautiful rosewood veneer cabinet with solid copper Viborg binding posts. Crossover will use nice custom made MKP caps and heavy gauge inductors.

-9c7ff4bc-37ec-40dc-b01a-f12ab7481c73-jpeg
Attached Images
File Type: jpeg 9C7FF4BC-37EC-40DC-B01A-F12AB7481C73.jpeg (45.9 KB, 104 views)
__________________
XRKaudio Store // Manufacturer’s Forum
  Reply With Quote
Old 5th October 2021, 05:12 AM   #266
peppennino is offline peppennino  Italy
Galactic Hitchhiker
diyAudio Member
 
peppennino's Avatar
 
Join Date: Oct 2005
Location: Πανορμος
Truly beautiful, X!
__________________
Lifetime Greenhorn | SL1210MK2 + DL103 | 834p TRLH + α2δ PSU1 | UBP-X800 + Linear PSU | Rasp 3B+ | JEL TDA1541/6CG7 | B1R2 | Aleph JZen (WIP) | Π 4 | Magic Smoke 2021
  Reply With Quote
Old 7th October 2021, 04:27 PM   #267
xrk971 is online now xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
On the virtual bench, I am working with JPS64 to develop a main board for a new 100w Class A amp. This holds the soft start, an active bridge and CRCRC PSU, front end HV balanced preamplifier, and solid state relay speaker protection.

-7c4b7b07-6114-4b90-9bc7-66c643597e09-png
Attached Images
File Type: png 7C4B7B07-6114-4B90-9BC7-66C643597E09.png (421.0 KB, 75 views)
__________________
XRKaudio Store // Manufacturer’s Forum
  Reply With Quote
Old 7th October 2021, 04:32 PM   #268
dBel84 is offline dBel84  United States
diyAudio Member
 
Join Date: Jul 2006
Location: midwest USA ~ WI
That will be a handy circuit for many amp platforms
  Reply With Quote
Old 7th October 2021, 05:30 PM   #269
korpberget is offline korpberget  Norway
diyAudio Member
 
Join Date: Mar 2016
Location: Lillehammer
Too much at the same time as usual.
Rotel power amp, timer circuit to testdrive inverter fridge compressors, my diy speakers, Linhai Bighorn quad, a flood light etc. And a can of beer
  Reply With Quote
Old 13th October 2021, 01:04 PM   #270
xrk971 is online now xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
On the bench was the SuSyLu and more FFT measurements with a different analyzer. I think the Focusrite is damaged as noise was high. Switched to an inexpensive Behringer UM-2. Works well enough for this application as long as you don’t need to go less than 0.001%THD.

SuSyLu Where Are You?

A couple of good findings:

1. Amp displays dominant second harmonic distortion profile up to about 28w. About that the third harmonic starts to get higher. Higher order harmonics are all monotonously descending and at lower powers there is not much above 4th or 5th harmonic. All this is consistent with typical SE Class A amp behavior. Predictions show dominant third harmonic but that assumes perfect balance on both legs, rarely achieved in reality on a big discrete amp like this. So this is a fortuitous result and I’ll take it.

2. At max power of 100w, the measured THD is 1.4% and this is consistent with prediction that THD would be 1.47% is good and shows that the model is not too far off. It also means that for the majority of music played at or below 25wrms level, the dynamic peaks up to 6dB more will still have a nice harmonic profile.

3. The 60Hz mains peak is very low and the (2f) mains peak at 120Hz is only -95dB below peak signal. A very good result for a linear CRCRC PSU. Consistent with the Fluke 101 measurement of 0.2mV rms.

4. The noise floor baseline is also very good at -125dB and there is little noise in the higher frequency band above 1kHz. This should make for a very silent black background for music playback.

This is 8w:
Click the image to open in full size.

This is 28w:
Click the image to open in full size.

This is the noise background with no signal:
Click the image to open in full size.
__________________
XRKaudio Store // Manufacturer’s Forum
  Reply to this post

Reply


Hide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Great Lunar Eclipse tonight Pano Everything Else 11 28th August 2007 08:38 PM
Recapped the Imperial 7s tonight geaugafletcher Multi-Way 2 26th April 2006 04:26 PM
Getting ready to buy my speakers tonight... mazeroth Multi-Way 22 29th July 2004 07:16 PM
felt an earthquake tonight ultrachrome The Lounge 3 3rd June 2003 10:14 AM


New To Site? Need Help?

All times are GMT. The time now is 01:07 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 13.64%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki