Dx Blame MKIII-Hx - Builder's thread - Page 94

currentflow · 3rd February 2012, 02:57 PM

Quote:

Originally Posted by space2000

I am listening from 8ohms loudspeaker, No other then this.

That speaker load should be fine. Is the speaker possibly damaged? (sorry to ask!) Are the transistors you've fitted exactly those as specified? If not, do the ones fitted have the same pinouts?

Try using a different pair of output transistors after disconnecting the originals, then re-adjust the bias setting.

The lower end of R5 isn't open-circuit to ground by any chance?

As BMW850 suggests, you may have one or more fake transistors...

Regards,
currentflow

BMW850 · 3rd February 2012, 03:12 PM

I'm listening now without the 1uF capacitor in the signal path, I short-circuit this cap with a wire.
Much more depth in the sound

Regards,
Rudy

AndrewT · 3rd February 2012, 05:08 PM

where is the 1uF?
What does it replace?
Where is the short circuit?
What is more depth?

a.wayne · 3rd February 2012, 05:52 PM

It's the input coupling cap Andrew .....

space2000 · 10:55 PM

Thanks. I will check my speaker and the transistors again. it could be cause by fake or weak transistor at output. I don't like MJE. Can i change some transistors?

T8=2sc4793
T9=2sa1837
T10=2sc4793
T11=2sa1837

All these parts are easy to get here.

Regards
Michael

space2000 · 4th February 2012, 01:26 AM

My speaker has no problem.

I must note that I am using output Power transistor 2SC5200 and 2SA1943. It can be use in this amp as noted ealier in this forum.

Regards
Michael

currentflow · 4th February 2012, 09:03 AM

Quote:

Originally Posted by space2000

My speaker has no problem.

I must note that I am using output Power transistor 2SC5200 and 2SA1943. It can be use in this amp as noted ealier in this forum.

Regards
Michael

Your transistor substitutes as listed should work fine. Other areas to investigate include PCB track breaks and/or shorts and faulty components. Do you have an oscilloscope?

Regards,
currentflow

BMW850 · 01:01 PM

Have a video made of the amplifier with my mobile phone.
Hopefully I have the music not too loud, no talking about distortion sounds

Here you can also see my acoustics ceiling treatment.
You also see my jumper/wire over the 1uF, it sound much better without the 1uF.

Special Note about the 1uF cap, you can do this only if you use a preamplifier, NOT with a passive volume control.
I'm not going in discussion why not, some things come not from myself.
You have chance you get than a problem, because you are going to hear the steps of the passive volume control.
You also select a piece of DC along with your passive volume control
My Fettle Preamp (and 99% of other preamps) has a output capacitor, which stops the DC, and also before the pre.

Video now uploading (748mb):
http://www.youtube.com/watch?v=X0pkmtH0058

Regards,
Rudy

a.wayne · 4th February 2012, 01:18 PM

Video blocked ...............

BMW850 · 4th February 2012, 02:33 PM

Video may contain content that is in possession of or administered by these entities:
• Entity: WMG and UMG content type: audio recording.

Therefore, your video is blocked in the following locations:
American Samoa, Guam, Northern Mariana Islands, Puerto Rico, United States, United States Minor Outlying Islands, United States Virgin Islands.

Nowadays one can download music anywhere in the highest bitrate and a simple video is blocked by youtube

3rd February 2012, 03:12 PM	#932
BMW850 diyAudio Member Join Date: Aug 2004 Location: North East of the Netherlands	I'm listening now without the 1uF capacitor in the signal path, I short-circuit this cap with a wire. Much more depth in the sound Regards, Rudy __________________ It’s not what you know, but who you know “and where they are”

3rd February 2012, 05:08 PM	#933
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	where is the 1uF? What does it replace? Where is the short circuit? What is more depth? __________________ regards Andrew T.

3rd February 2012, 10:39 PM	#935
space2000 diyAudio Member Join Date: Mar 2008	Thanks. I will check my speaker and the transistors again. it could be cause by fake or weak transistor at output. I don't like MJE. Can i change some transistors? T8=2sc4793 T9=2sa1837 T10=2sc4793 T11=2sa1837 All these parts are easy to get here. Regards Michael Last edited by space2000; 3rd February 2012 at 10:55 PM.

4th February 2012, 12:43 PM	#938
BMW850 diyAudio Member Join Date: Aug 2004 Location: North East of the Netherlands	Have a video made of the amplifier with my mobile phone. Hopefully I have the music not too loud, no talking about distortion sounds Here you can also see my acoustics ceiling treatment. You also see my jumper/wire over the 1uF, it sound much better without the 1uF. Special Note about the 1uF cap, you can do this only if you use a preamplifier, NOT with a passive volume control. I'm not going in discussion why not, some things come not from myself. You have chance you get than a problem, because you are going to hear the steps of the passive volume control. You also select a piece of DC along with your passive volume control My Fettle Preamp (and 99% of other preamps) has a output capacitor, which stops the DC, and also before the pre. Video now uploading (748mb): http://www.youtube.com/watch?v=X0pkmtH0058 Regards, Rudy __________________ It’s not what you know, but who you know “and where they are” Last edited by BMW850; 4th February 2012 at 01:01 PM.

4th February 2012, 02:33 PM	#940
BMW850 diyAudio Member Join Date: Aug 2004 Location: North East of the Netherlands	Video may contain content that is in possession of or administered by these entities: • Entity: WMG and UMG content type: audio recording. Therefore, your video is blocked in the following locations: American Samoa, Guam, Northern Mariana Islands, Puerto Rico, United States, United States Minor Outlying Islands, United States Virgin Islands. Nowadays one can download music anywhere in the highest bitrate and a simple video is blocked by youtube __________________ It’s not what you know, but who you know “and where they are”


	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

3rd February 2012, 05:52 PM	#934
a.wayne diyAudio Member Join Date: May 2008 Location: Front Row Center	It's the input coupling cap Andrew .....

4th February 2012, 01:26 AM	#936
space2000 diyAudio Member Join Date: Mar 2008	My speaker has no problem. I must note that I am using output Power transistor 2SC5200 and 2SA1943. It can be use in this amp as noted ealier in this forum. Regards Michael

4th February 2012, 01:18 PM	#939
a.wayne diyAudio Member Join Date: May 2008 Location: Front Row Center	Video blocked ...............

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Dx Blame ST - Builder's thread - post pictures, reviews and comments here please.	destroyer X	Solid State	1571	Yesterday 09:50 PM
group buy for DX Blame MKIII Hx PCBs	ByronInLawrence	Group Buys	246	18th February 2012 08:33 AM
Dx Blame MKIII Supercharged will soon be released	destroyer X	Solid State	335	20th November 2011 03:37 AM
Group By: DX Blame MKIII Hx boards	ByronInLawrence	Group Buys	9	19th July 2011 07:21 AM
Dx Blame MKII, an obvious evolution from the Dx Blame ES/ST	destroyer X	Solid State	4	25th September 2010 06:41 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read