♫♪ My little cheap Circlophone© ♫♪ - Page 66 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 11th February 2012, 04:27 PM   #651
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
I have made a quick physical test of the CFP version:

♫♪ My little cheap Circlophone© ♫♪

Click the image to open in full size.

I first attempted a direct plug-in replacement of the two input transistors by two composites, including their 15K BE resistors, without changing anything else.
There was a small (200~300mV) HF oscillation on the output waveform.

I then added the 270p/100R specific compensation network, and the oscillation went away.
I didn't care to make the rest of the modifications, and connected it to a source and speaker: as I write, I am listening to it and everything seems OK
So, after all the predictions of the sim were not that bad.
I would not recommend such a careless attitude to anybody else, but it proves it is safe enough for others to begin experiments.

My "test-bed" used the standard recommended components, except for the OP devices which were BD249C instead of TIP3055
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 11th February 2012, 05:37 PM   #652
diyAudio Member
 
terranigma's Avatar
 
Join Date: Feb 2007
Quote:
Originally Posted by kenpeter View Post
I'm merely suggesting that Elvee has the patience of a saint.
Maybe that's the one of the significant reasons of ability of design such topologies.

Quote:
Originally Posted by Elvee View Post
I have made a quick physical test of the CFP version:

♫♪ My little cheap Circlophone© ♫♪

[IMG]
I would not recommend such a careless attitude to anybody else, but it proves it is safe enough for others to begin experiments.

My "test-bed" used the standard recommended components, except for the OP devices which were BD249C instead of TIP3055
Thank you for good news I'm almost hopeless to find some Philips BDT85/87 for my project. Their specs despite their little case (TO220) has surprised me. TIP and BD series from TI wink at me for a while.
  Reply With Quote
Old 12th February 2012, 12:57 PM   #653
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by kenpeter View Post
I'm merely suggesting that Elvee has the patience of a saint.
He does have the patience of a saint.
Quote:
Originally Posted by Elvee View Post
I have made a quick physical test of the CFP version. . . as I write, I am listening to it and everything seems OK
Congrats! How do you like its subjective performance? Are there any noticeable differences except for more gain?

Quote:
Originally Posted by Elvee View Post
I cannot find reliable models for these transistors; anyway, that is something that needs to be tested for real, a sim alone is not able to tell the complete story.
Here was the amount of data that I was able to retrieve:
Hitachi 2sd699 (12pF), 2sb649
.model 2SD669 NPN (IS=5p NF=1 BF=250 ISE=5p NE=1.5 IKF=3 VAF=150 RB=1 RC=0.25 RE=0.25 TF=1.14ns CJC=50p )
.model 2SB649 PNP (IS=5p NF=1 BF=250 ISE=10p NE=1.5 IKF=3 VAF=75 RB=1 RC=0.25 RE=0.25 TF=1.14ns CJC=50p )
Onsemi MJE344 (15pF but maybe too slow), MJE350
Toshiba 2sc3421 (15pF), 2sa1358
Toshiba 2sc5171 (16pF), 2sa1930

All of those are generally available, and you could mix-n-match if you wanted to. And, if you want samples, PM me with your mailing address.

P.S.
I did finally manage to acquire some of those 1980's Philips BD140's, and when on unregulated power (meaning exposed to our multiple daily power surges), perhaps I could use 33v rails. This isn't really more powerful than what I already had, but maybe there an audible difference to explore. With these considerations and more, I've been shopping for speaker efficiencies in the mid 90's. . .
  Reply With Quote
Old 12th February 2012, 04:20 PM   #654
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by danielwritesbac View Post
Congrats! How do you like its subjective performance? Are there any noticeable differences except for more gain?
Since I have tin ears, my subjective assessments are essentially based on negatives
I am satisfied when I hear no noise, no crossover distortion, no dynamic artifacts and no bandwidth anomalies.

Here, I left the gain unchanged, I just wanted to make a reality check with the CFP.
I am confident it will work properly at higher closed loop gains


Quote:
Here was the amount of data that I was able to retrieve:
Hitachi 2sd699 (12pF), 2sb649
.model 2SD669 NPN (IS=5p NF=1 BF=250 ISE=5p NE=1.5 IKF=3 VAF=150 RB=1 RC=0.25 RE=0.25 TF=1.14ns CJC=50p )
.model 2SB649 PNP (IS=5p NF=1 BF=250 ISE=10p NE=1.5 IKF=3 VAF=75 RB=1 RC=0.25 RE=0.25 TF=1.14ns CJC=50p )
Onsemi MJE344 (15pF but maybe too slow), MJE350
Toshiba 2sc3421 (15pF), 2sa1358
Toshiba 2sc5171 (16pF), 2sa1930
I had found similar models, but they are too simplified, and the CJC value amongst other things is suspicious.
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 12th February 2012, 05:40 PM   #655
diyAudio Member
 
terranigma's Avatar
 
Join Date: Feb 2007
I'm listening the setup below for a few hours, it is just wonderful! I couldn't imagine 200kHz RCA BDY29's will perform so beautiful. Maybe it is the benefit of their outstanding SOAR.

Another thing is after realizing that 1N5819 is not a good thing as D7 according previous comments, my noise performance get closed to actual one now with using BAT85 as D7. Frankly, I hadn't any idea about the difference between them until those comments and nice graps by Elvee. This journey became educational for me as being as joyful same time.

C12: 180p
D7: BAT85
Q5-Q6: Transitron 2N5858 (200MHz, 12pF)
Q11-Q12: Harris BD140 (No datasheet found)
Q1-Q3-Q4: Philips BC560C (Hfe ~540)
Other small transistors: Philips BC557B, BC547B, 2SC2240
Power Transistors: RCA BDY29
Without C11 of course.

Last edited by terranigma; 12th February 2012 at 05:49 PM.
  Reply With Quote
Old 12th February 2012, 10:35 PM   #656
diyAudio Member
 
Join Date: Dec 2010
Originally Posted by Elvee
I cannot find reliable models for these transistors;

I've got these 2 models, I don't know how good they are; You might be able to use them.

Regards,
Ted

.MODEL 2SD669 NPN (IS=12.0986F NF=0.8124 BF=255.1933 IKF=0.7146 ISE=15.842F NE=1.1041 VAF=88.4468 RC=0.48 RB=1.9 IRB=0.1787 RBM=0.475 RE=12M VAR=24.146 IKR=2.3712 ISC=3.8496F NC=1.135 NR=0.8027 BR=9.478 CJC=53.91P VJC=0.5 MJC=0.418 CJE=59.31P VJE=0.5 MJE=0.418 TF=0.936N XTF=0.318 ITF=0.8168 VTF=3.5927 TR=53.5038N XCJC=0.618 FC=0.543 XTB=1.487 XTI=2.818 Vceo=120 Icrating=1.5 mfg=Hitachi)

.MODEL 2SB649 PNP (IS=56.5F NF=1 BF=220 VAF=197 IKF=0.6 ISE=32.4p NE=2 BR=4 NR=1 VAR=20 IKR=0.9 RE=0.479 RB=1.92 RC=0.192 XTB=1.5 CJE=202p VJE=1.1 MJE=0.5 CJC=65.1p VJC=0.3 MJC=0.3 TF=1.14N TR=789N Vceo=-120 Icrating=-1.5A mfg=Hitachi)
  Reply With Quote
Old 13th February 2012, 12:26 AM   #657
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Here is the input system that I'm using right now.

I'm not sure if the zener protector (parallel with the 10k input load) is the right value for everyone? How much voltage does an ordinary CD player output? Well, the computer likes to output a lengthy, subharmonic noise during start up and power management cycling, causing "x-max screen saver" and the zener thing shown, reduces those problems, and it blocks some RF, since zeners are modestly capacitive.

This has Ken's soft clip adapter too. I've modified it to remove ringing by adding a 470R resistor series to the diodes. A 1k didn't work there (neither ringing nor soft clip), so I picked up the 470R from the desk and used it. A smaller value, like 330R, probably works similarly.
That soft clip adapter does soft clip as shown. Man, you can really crank it up. For reference, I have 31v rails and an effective 70w is no problem, but now it does that cleanly. The resistors on that divider are 150R with 330R but I hunted through a few with the ohmmeter till I found some that came up a bit short so that the total would be really close to 470R, since the divider has replaced R16.
Attached Images
File Type: gif inputmods.gif (14.4 KB, 528 views)
  Reply With Quote
Old 13th February 2012, 05:35 AM   #658
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Wow, I tried 2N3109 for Q14, and then removed it. Sonic signature did 7khz at +11, the resolution seems to have decreased and the nice big open sound was gone. I also tried the RC filter in both locations, but that didn't have much effect. So, anyway, the amp was better with the zeners.
Attached Images
File Type: gif Circlophone70.gif (28.8 KB, 388 views)
  Reply With Quote
Old 13th February 2012, 07:19 AM   #659
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by albina View Post
Originally Posted by Elvee
I cannot find reliable models for these transistors;

I've got these 2 models, I don't know how good they are; You might be able to use them.

Regards,
Ted

.MODEL 2SD669 NPN (IS=12.0986F NF=0.8124 BF=255.1933 IKF=0.7146 ISE=15.842F NE=1.1041 VAF=88.4468 RC=0.48 RB=1.9 IRB=0.1787 RBM=0.475 RE=12M VAR=24.146 IKR=2.3712 ISC=3.8496F NC=1.135 NR=0.8027 BR=9.478 CJC=53.91P VJC=0.5 MJC=0.418 CJE=59.31P VJE=0.5 MJE=0.418 TF=0.936N XTF=0.318 ITF=0.8168 VTF=3.5927 TR=53.5038N XCJC=0.618 FC=0.543 XTB=1.487 XTI=2.818 Vceo=120 Icrating=1.5 mfg=Hitachi)

.MODEL 2SB649 PNP (IS=56.5F NF=1 BF=220 VAF=197 IKF=0.6 ISE=32.4p NE=2 BR=4 NR=1 VAR=20 IKR=0.9 RE=0.479 RB=1.92 RC=0.192 XTB=1.5 CJE=202p VJE=1.1 MJE=0.5 CJC=65.1p VJC=0.3 MJC=0.3 TF=1.14N TR=789N Vceo=-120 Icrating=-1.5A mfg=Hitachi)

Thanks, the 2SD669 looks more complete, but the Cjc still looks fishy: it is too high to match with the datasheet figure, and it is practically identical to the Cje.
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 13th February 2012, 07:59 PM   #660
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by terranigma View Post
. . . C12: 180p. . .
I'm so curious. You like fine tuning C12, and I wonder for what part of the audio band does tuning that have the largest effect? What varieties are possible by tuning C12?
Thanks!
  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
Need help with OB design - cheap, cheap, cheap djn Multi-Way 38 30th May 2010 06:26 AM
Scosche SPL meter: Cheap find with potential, or cheap junk? theAnonymous1 Everything Else 5 11th October 2006 03:40 AM
Alpine cda-9831 vs. 9833 vs. 9835 cbecker33 Car Audio 3 10th December 2004 12:47 PM


New To Site? Need Help?

All times are GMT. The time now is 10:07 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2