Dx Blame ST - Builder's thread - post pictures, reviews and comments here please.

ostripper · 2010-11-23 2:58 am

At "nuclear" volumes the TMC kicks in. Also, the sound stays the same even with gross misbiasing (TMC "eats" crossover distortion).
Overall , this is the "perfect amp" , but with TMC .. it stays perfect over a greater range.
My problem with this amp is that it is so distortion-less , the only thing left was the junction noise of the input pair... at ANY volume. So , the cascode/MPSA18's are the next step , plus big FAT audiophile input caps

(C1 - Below).

(Below 2) shows the correction signal which is fed back to the miller loop , it correlates to the crossover point. The remaining high order distortion (produced by the outputs) is also gone in an FFT.

OS

smartx21 · 2010-11-23 3:09 am

Mamak said:
hello.i built dx blame st 1.5.my problem is when start up without play song it become very hot.if play the song more heat produce.i follow and use all recommended component in this thread.why this happen and solution to me?

Have you adjusted bias correctly? Removing rail fuses, maintaining series 100 ohm resistors, you should read something around 4.7VDC through their leads. Start with a high value for the trimmer (> 300 ohms), then lower it while adjusting.

niss_man · 2010-11-23 5:16 am

The Blame amps I have built run very cool. Any cooler and you'd think I lived in Antartica. Less than luke warm to touch after playing for an hour at loud levels. You will need to provide more info to the smart guys here (I am excluded) for them to make a feasable comment. Some pictures would help. Have you a camera with a macro mode?

Regards

Niss_man

Mamak said:
hello.i built dx blame st 1.5.my problem is when start up without play song it become very hot.if play the song more heat produce.i follow and use all recommended component in this thread.why this happen and solution to me?

Mamak · 2010-11-23 5:55 am

smartx21 said:
Have you adjusted bias correctly? Removing rail fuses, maintaining series 100 ohm resistors, you should read something around 4.7VDC through their leads. Start with a high value for the trimmer (> 300 ohms), then lower it while adjusting.

you are right.when i remove the fuse , heatsink is cool while playing song.but when i increase volume sound bass more broken.this fuse using or not?or remove while setting bias?when multimeter parellal with resistor at fuse i get more than 6 volt.how to set bias?

niss_man · 2010-11-23 6:14 am

Mamak said:
you are right.when i remove the fuse , heatsink is cool while playing song.but when i increase volume sound bass more broken.this fuse using or not?or remove while setting bias?when multimeter parellal with resistor at fuse i get more than 6 volt.how to set bias?

You shouldn't play music with the fuses removed! What smartx21 means is have no music playing. No inputs. Just measure across the 100ohm resistor (across fuse terminals). The basic setting is 4.7v. This means a standby current of 47mA. Still if you have 6v accross the fuse (without input) 60mA is still acceptable. You probably have issues elsewhere. Photos?

Regards

Niss_man

Mamak · 2010-11-23 6:22 am

niss_man said:
You shouldn't play music with the fuses removed! What smartx21 means is have no music playing. No inputs. Just measure across the 100ohm resistor (across fuse terminals). The basic setting is 4.7v. This means a standby current of 47mA. Still if you have 6v accross the fuse (without input) 60mA is still acceptable. You probably have issues elsewhere. Photos?

Regards

Niss_man

thanks smartx21.i get the solution.my trimmer install problem.now i can setting bias.sound good.bass smooth.i like it.heatsink cool.but why must 4.7 volt?this value depend on power supply voltage or speaker load or this standard value could i just follow?

Mamak · 2010-11-23 8:51 am

this amp powerfull.can i add sc5200 to get more power?and what must i change for standart dx blame st pcb?

smartx21 · 2010-11-23 9:21 am

Mamak said:
this amp powerfull.can i add sc5200 to get more power?and what must i change for standart dx blame st pcb?

The value of 4.7VDC is a project guideline. Removal of fuses only for adjustments. Here you can find specs for a more powerful DX Blame ST, the MKII Supercharged: www.dx.kinghost.net. Besides doubling OPs, rail voltages are raised, and some parts values do alter. Be careful and enjoy!

dadod · 2010-11-23 10:15 am

Blame ST + TMC

TMC elements I used are: )look at schematic OS presented in #1119)
C13=150p, C12=470p and R19=220R
Simulated distortion is: (I do not have equipmnt to measure it on real amp)

Circuit: * C:\dado\Audio\DadoAmp\DX-blme-st-TMC.asc

Direct Newton iteration for .op point succeeded.
Heightened Def Con from 8.13802e-012 to 1.00814e-009
Fourier components of V(vin)
DC component:1.35985e-005

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 3.000e+03 5.060e-01 1.000e+00 -0.01° 0.00°
2 6.000e+03 1.890e-08 3.735e-08 -109.21° -109.20°
3 9.000e+03 1.048e-09 2.071e-09 128.10° 128.11°
4 1.200e+04 9.838e-10 1.944e-09 -166.59° -166.59°
5 1.500e+04 1.255e-09 2.481e-09 12.46° 12.46°
6 1.800e+04 2.420e-09 4.783e-09 -6.04° -6.04°
7 2.100e+04 3.585e-09 7.085e-09 8.81° 8.82°
8 2.400e+04 5.019e-09 9.919e-09 -2.20° -2.19°
9 2.700e+04 5.629e-09 1.113e-08 7.64° 7.65°
Total Harmonic Distortion: 0.000004%

Fourier components of V(vout)
DC component:-0.0176293

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 3.000e+03 1.378e+01 1.000e+00 -0.49° 0.00°
2 6.000e+03 4.255e-05 3.088e-06 -120.73° -120.24°
3 9.000e+03 8.061e-06 5.850e-07 162.67° 163.16°
4 1.200e+04 1.039e-05 7.538e-07 179.46° 179.95°
5 1.500e+04 7.615e-06 5.526e-07 171.69° 172.18°
6 1.800e+04 6.895e-06 5.004e-07 -178.84° -178.35°
7 2.100e+04 6.583e-06 4.777e-07 166.70° 167.19°
8 2.400e+04 5.110e-06 3.709e-07 -177.22° -176.73°
9 2.700e+04 6.143e-06 4.458e-07 164.07° 164.56°
Total Harmonic Distortion: 0.000340%

It could be lowered even more but I have gone for better stability!!!!

Simulated distorton for Blame ST with Miller compensation:

Circuit: * C:\dado\Audio\DadoAmp\DX-blme-st.asc

Direct Newton iteration for .op point succeeded.
Heightened Def Con from 8.13802e-012 to 1.00814e-009
Fourier components of V(vin)
DC component:1.36071e-005

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 3.000e+03 5.060e-01 1.000e+00 -0.00° 0.00°
2 6.000e+03 1.693e-08 3.346e-08 -149.21° -149.20°
3 9.000e+03 1.177e-08 2.327e-08 85.96° 85.96°
4 1.200e+04 7.397e-09 1.462e-08 177.52° 177.53°
5 1.500e+04 2.137e-08 4.223e-08 78.32° 78.32°
6 1.800e+04 2.674e-09 5.285e-09 173.90° 173.90°
7 2.100e+04 2.887e-08 5.705e-08 73.61° 73.61°
8 2.400e+04 1.441e-09 2.847e-09 10.52° 10.53°
9 2.700e+04 2.964e-08 5.858e-08 68.23° 68.23°
Total Harmonic Distortion: 0.000010%

Fourier components of V(vout)
DC component:-0.0176098

Harmonic Frequency Fourier Normalized Phase Normalized
Number [Hz] Component Component [degree] Phase [deg]
1 3.000e+03 1.378e+01 1.000e+00 -0.22° 0.00°
2 6.000e+03 4.406e-05 3.197e-06 -159.06° -158.85°
3 9.000e+03 2.767e-05 2.008e-06 100.50° 100.71°
4 1.200e+04 2.606e-05 1.891e-06 177.24° 177.46°
5 1.500e+04 4.822e-05 3.499e-06 91.98° 92.19°
6 1.800e+04 1.992e-05 1.446e-06 176.89° 177.11°
7 2.100e+04 6.358e-05 4.614e-06 87.83° 88.05°
8 2.400e+04 1.526e-05 1.107e-06 176.62° 176.84°
9 2.700e+04 6.315e-05 4.583e-06 86.13° 86.34°
Total Harmonic Distortion: 0.000870%

dado

niss_man · 2010-11-23 10:46 am

Figures are nice but has anyone heard the Blame ST with TMC mod with their own ears, or only on simulated on spice? If anyone has actually heard the difference using their ears could they please say if there is any audible difference between the 2 ?

Dadod. Have you heard of a place called Oroslavje?

Regards

Niss_man

dadod · 2010-11-23 12:02 pm

Hi niss,
Yes I have heard and it is qute closse to Zagreb were I live.
I am listening Blame ST-TMC, but do not have equipment to measure distortion.
dado

Mamak · 2010-11-23 12:46 pm

niss_man said:
You shouldn't play music with the fuses removed! What smartx21 means is have no music playing. No inputs. Just measure across the 100ohm resistor (across fuse terminals). The basic setting is 4.7v. This means a standby current of 47mA. Still if you have 6v accross the fuse (without input) 60mA is still acceptable. You probably have issues elsewhere. Photos?

Regards

Niss_man

this my picture.stereo dx blame st amp and voltage regulator by apex design.
i interested with this amp.can anybody give way to add 3 pair or 4 pair of 2sc5200 to get more power output.

Mamak · 2010-11-23 12:48 pm

destroyer X said:
Soon we gonna have all stuff at Greg Erskine home pages too.

Greg's Web Site

down this page, attached the schematic and layout...much more to come!

regards,

Carlos

what different between this circuit with from ?

smartx21 · 2010-11-23 1:23 pm

Mamak said:
what different between this circuit with from * ?

I think you should read and follow this thread:

http://www.diyaudio.com/forums/soli...tions-dx-blame-mkii-supercharged-release.html

Regards,
Max.

Dacuycoy · 2010-11-23 1:51 pm

dadod said:
Hi Carlos,
I finished Blame-ST but with the touch. After reading about TMC by Edmond Stuart I could not but try it. "http://www.diyaudio.com/forums/solid-state/94676-bob-cordell-interview-negative-feedback-304.html"
Good start was Blame ST and here it is, Blame-ST-TMC.
Voltage is +-40V a bit more and the feedback resistance a 22k/820 same ratio but higher input resistance. PCB hand made.
The loudspeakers are hand made Seas woofer and mid/high ribon by Newform Research.
I like the sound of the combination very much.
Here is schematic and LTSpice simulation.

hi dadod, can you share your pcb design

Dacuycoy · 2010-11-23 2:02 pm

Mamak said:
this my picture.stereo dx blame st amp and voltage regulator by apex design.
i interested with this amp.can anybody give way to add 3 pair or 4 pair of 2sc5200 to get more power output.

q8 must be in fixed in the main heatsink

a.wayne · 2010-11-23 5:14 pm

smartx21 said:
The value of 4.7VDC is a project guideline. Removal of fuses only for adjustments. Here you can find specs for a more powerful DX Blame ST, the MKII Supercharged: . Besides doubling OPs, rail voltages are raised, and some parts values do alter. Be careful and enjoy!

Uncle Charlie is moving along nicely ....

niss_man said:
Figures are nice but has anyone heard the Blame ST with TMC mod with their own ears, or only on simulated on spice? If anyone has actually heard the difference using their ears could they please say if there is any audible difference between the 2 ?

Dadod. Have you heard of a place called Oroslavje?

Regards

Niss_man

I believe OS had commented on it , it was later edited ....he did believe the TMC mod made the amp better ...

ostripper · 2010-11-23 5:45 pm

a.wayne said:
Uncle Charlie is moving along nicely ....

I believe OS had commented on it , it was later edited ....he did believe the TMC mod made the amp better ...

It absolutely is worth the addition of 4 pads (2 components) which can be omitted/ jumpered for traditional compensation. I do it like (below) , the PCB reflects this as well.
OS

dadod · 2010-11-23 5:45 pm

Hi Dacuycoy,
PCB is very similar to original DX blame, just TMC possibility added, and feedback takeout point changed a bit according to Self.
dado

smartx21 · 2010-11-23 6:21 pm

a.wayne said:
Uncle Charlie is moving along nicely ....

He is really away for a while, and I am not his representative. I only try to help, since I built this amp twice and know these obvious things.
Regards,
Max.

Dx Blame ST - Builder's thread - post pictures, reviews and comments here please.

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