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Blame MKIII-HX

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I do not know...i just go to watch my own threads

my own amplifiers..i do not use to visit other threads or forums...i have already a lot of things to do.

You see... i do not sell stuff, i do not have pcboards, no parts...my job is creating, design, adaptation, tweak of amplifiers, redesign, modification, improvement..and the one i have elected is Blameless and this was the final solution..the best ever listened by me..i do not even watch others.

I use to build prototype, to test and torture, to simulate, to prepare schematic, to ask cooperators (Dx Layout people) to prepare pcboard layout, i use to give muy opinions on that...i ask my people to produce and sell pcboards..i do not mess with money myself.

Uncle charlie is a real DIYer since i was 9 years old (53 years before)...this is my passion, my stuff...business is another thing that i hate and others take care of that...from time to time i receive gifts for that..some pcboards and some parts..but this is all.

I have my own employment in the Government...this is a job for life long..almost retired.... i do not make my living on audio.

DIY store?...... do we have that?.... this is nice.

This amplifier...well... i cannot remember exactly and i am afraid to say the wrong builder's ...but it looks to me was made by someone from Mid east inside the diySMPS forum.... as i said...not sure about that.

The real builder..i would love him to come to take paternity.

regards,

Carlos
 
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I have some news about my troubles. First, I found where the horrible looking square waves came from. It is my scope. I saw it yesterday again so I hooked the probe to the calibration bar on the scope and see the same shape. I checked channel one and the shape is fine. Seems some of the switches in the scope are getting dirty.

Anyway, there is still a little something happening at the point of clipping but I'm not going to worry about that as I will never play it that loud. I did find the problem with the nonworking channel. When doing the mods that Carlos suggest, I changed R22 instead of R21. I have fixed that and now it is playing and the heat at the VAS is greatly reduced. Very cool. I am still having trouble getting the bias set. What is the best way to measure it? I have tried using an ammeter on the rail, using a 10R 10w resistor in place of the fuse and tried measuring across a pair of the emitter resistors. With a 3k3 resistor in R21 I can't get it to bias at all. 0.0mv across the emitter resistors. That is class B if I understand correctly. Any help here will be appreciated.

Thanks, Terry
 
Hi Carlos,

Yes I saw your explanation. Thanks for taking the time. I'm sure it will help others who are just now building the amp. Mine plays plays fine now. Once I get the final heatsinks I will mount it in a cabinet so I can do final adjustments. Then it will join my stack of amps and get get A/B/C/D/E/F/G'd. He he he. Fun stuff!!!
 
The schematic used to produce these pcboards Meanman

Have offered is in Meanman hands...i have some but they are updated schematics that may not fit this pcboard...so.... this is to Meanman to answer you.

Several group buys and produced in several places and in several batches..so... there are some differences.

Red Boards, made by Meanman, are based in one particular schematic..and this is the one you should search for.

In the thread, Dx Blame MKIII, there you will have the first, second, and final schematic....search in descending order if you will produce your own pcboard... search in descending will allow you to find the last schematic posted...and the last schematic posted is the most modern one..... i do think you will find an optimized schematic as people have asked me to reduce third harmonics to make it even better in sonics.

The original thread is here:
http://www.diyaudio.com/forums/soli...me-mkiii-supercharged-will-soon-released.html

Past builder's thread:
http://www.diyaudio.com/forums/solid-state/193759-dx-blame-mkiii-hx-builders-thread.html


regards,

Carlos
 
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Ok thanks Carlos I will look more or contact Meanman this is always a problem with all amplifier designs that evolve over a period of time different people tweek things to suit their needs the problem is tracing the thread backwards over many hundreds of posts on many threads.

Other problem is the search engine on this forum is a little lacking but do not worry we will get there in the end.
 
Hi Earthquake.

You are right, there is a lot to read through. Ranchu32 started a new thread to try and gather the info in a smaller thread but even that is getting long. You can find it here.
I put together a parts list by modifying Byron's list based on the latest schematic I could find. You can find it there. I know that I had to make some changes once I got the amp built and I am looking over the BOM this morning to see if the changes are in there. I will report back once I have had a chance to finish. I will try to get the schematic, BOM and the board top-view with part numbers gathered up and posted together here and in that other thread too.

Blessings, Terry
 
Blameless concept...the amplifier i have used as reference

First time i build it i found it sterile ... without taste if it was a food...without salt if it was a steak....then i have tweaked as Self said the amplifier was only a "frame"... a "skeleton"... an idea of low distortion that should be researched.... a concept!

If he said this or not i am not sure...this is what i understood..then i started to work hard on it.

I made all i could using the instruments i had, scope, simulator and my ears and i found it the best amplifier i have ever listened too ... and i have assembled thousands ... within these thousands several different topologies ... i found it the best and i have ever followed this inspiration.

It is almost the same..also it is not the same ... does not sound the same..but it is hardly inspired ... the "frame" was copied for sure.

You all can see the differences ... compare the sound and the schematic and you gonna see all the hard work i have made.

There's no bootstrap in Blameless amplifier...this is the first difference you can see....and several other details that sounds good ... assemble one and other and come here to say the differences .... i would love to hear that.

Why dots? when i write i use to put dots in place of comma .... i was a Radio Amateur by 30 years long.

regards,

Carlos
 

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