Destroyer x Amplifier...Dx amp...my amplifier

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I have contacted Meanman but no response so far.

Just looking at the circuit diagrams of the amp and bearing in mind Carlos' remark about possible oscillations do not forget about baker's clamp diode (nte177 or bav21 or something faster) between the base of Q7 (2n5551) and the Q8 collector (mje15030) shown on one of the diagrams.

This Q8 transistor provides all voltage gain of the amplifier. Problem appears when the amp is overdriven and this transistors is driven deep into saturation and then there is delay when it comes out of saturation and oscillations occur.

When the amp gets into clipping this diode reduces the VAS gain for the negative part of the signal and in this way oscillations are prevented/killed.

Has any of you contacted Meanman? Any success?

cheers,
 
I have contacted Meanman but no response so far.

Just looking at the circuit diagrams of the amp and bearing in mind Carlos' remark about possible oscillations do not forget about baker's clamp diode (nte177 or bav21 or something faster) between the base of Q7 (2n5551) and the Q8 collector (mje15030) shown on one of the diagrams.

This Q8 transistor provides all voltage gain of the amplifier. Problem appears when the amp is overdriven and this transistors is driven deep into saturation and then there is delay when it comes out of saturation and oscillations occur.

When the amp gets into clipping this diode reduces the VAS gain for the negative part of the signal and in this way oscillations are prevented/killed.

Has any of you contacted Meanman? Any success?

cheers,
When?? Didn't recieve any mail or so . Or you did send it to my old account.
I start a groupsbuy this week.
 
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When?? Didn't recieve any mail or so . Or you did send it to my old account.
I start a groupsbuy this week.

I sent message to your DIYaudio name. I think it was meanman64. I see it is Meanman1964.

OK, important thing is that you are starting a new group buy. Would you roughly know price of two boards?

cheers,
PS I think Jim's pcbs require some track cutting and relinking. Authorized or not Carlos should claim royalties on boards produced and sold by Jim's Audio - assuming he did not get any.
 
Try Alex MM, he is the pcboard layout designer....

....so, he also has the right to explore this design.

Alex mm is active in audio, at least he is in my facebook building amplifiers,

trying other circuits and new ideas.

He can provide you layout, also gerbers if you decide to produce samples for

yourself and friends......ahahahahaha! ..... please, not the same quantity of

friends Jim has....it seems the whole world represents his frienship....in other

words, $ is his best friend.

I have no personnal interest to see this amplifier distributed by two main

reasons.....first one is because the unit had some troubles and i have no time to

dedicate, anymore, to this amplifier....so....problems you may face will not

receive help or follow up... i already did that...for long time working for free

at diy.

The other reason is that i may release another version, much better and to be

sold in Brazil only..... so...old models are now a days competition.... i am

competing with myself.... and i am a very good competitor with myself as i

am bothering me a lot.

Now a days i am working for money....not anymore for passion .... i have to

pay my daughter's College.....Medical School.....so...i cannot be playing with

that anymore.... now stuff is serious.

Another reason is that i have worked for 10 years plus, for free, for this

forum.....then forum decided to create a forum supported amplifier.....do you

know the one was chosen to create a design?..... was not me....so.... no

more effort here.

Try Alex.... he may have last revision pcboard......also a College teacher, from USA has

made and distributed pcboards....he may help you too.... search for this amplifier group buy and you may find the teacher

his name i cannot remember anymore as i am 66 old

regards,

Carlos
 
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Alexandru Pop is Alex MM name in facebook

Search Alexandru from Romania, he is the layout designer from MKIII model....he can provide pcboards, he can manufacture and sell if he want.

Jim audio PCBoards are defective...there's a problem in the circuit track...you will watch
in oscilloscope the trouble clearly.....other revisions were made.

I do not think Alexander may produce pcboards...i am just saying he can do it if he wants

regards,

Carlos
 
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Alex MM designed boards for Jim's Audio. Where we could find Alex MM? Is he a member of DIYaudio? Carlos, would you know his member name or email?

Is here anyone who has this amp in LTspice? That would make things easier.

There are a few things I would have done somewhat differently. If no one has LTSpice file of this amp I'll draw it in LT Spice and play with it but in the end it is good pcb layout which decides the final quality.

cheers,
 
Hello dear diyaudio members

I am read this thread for some time

Can I ask about DX amplifier,(I know I am too late for this query) how to make this amp work with +/-50VDC 300VA transformer, I know a more advanced model is available than dx amplifier on diyaudio like dx super A, Blame ST, ES but I want to make this amp and want 100W on 8Ohm load.what changes I have to make in the amp circuit please can someone help.
recently I make this amp, photo and the link is attached below they say its 100W in 8Ohm load.But I don't think so they use a single pair of 2sc5200 on the output can it possible.
construya un amplificador monofonico de 100 watts version 2.0
 

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I cannot remember my dear...a long time passed and uncle charlie

Is now a days very old.

Maybe someone skilled in design can redesign it to work with 50 volts.

I am distant form this forum by several years...now i am returning very slowly.

All information was posted in this same thread.... to answer you i have to read it entirelly once again...so...makes

more sense you to read directly..this way only one will read it entirelly

regards,

Carlos:)
 

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hello Rawaudio

I think we need to keep this section only for Dx's designs talkative subject that amplifier from Ampletos is not part of this area I suggest try other forums that talks about that particular amplifier design and they can help you if you speak Spanish try this forum they are many people there with lot of knowledge Foros de Electronica
I have seen Mr. Ampletos designs they are not bad at all just that I don't like the fact that you can not adjust bias that's all, I learn that is best to keep the same subject example if we talk about Dx amp X1 we gonna continue with that subject but if we add other designs that are not part of the main subject information then all will be really confused for the new readers I hope you understand.

Best Regards
Juan
 
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