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Need 150 to 200watts amplifier achematic

Posted 10th September 2010 at 01:44 PM by yoyomaster01

Hi to everyone!!!

I'm new i this site
I just want to ask for some pcb and schematic for a 200watts amplifier

Can P3A amplifier from ESP modified?
and add some more output tannies?
maybe 3 pairs?

I want to use MJE2955 and MJE3055 for the outputs.....

Any body?
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Old

Common emitter amplifier design II

Posted 9th September 2010 at 08:27 PM by wakibaki

In the earlier post, basic common emitter amplifier design, I made reference to increasing the gain of the amplifier by bypassing the emitter resistor R[SIZE="1"]E[/SIZE].

In this case the gain referred to is the AC gain, which is the signal gain, and which is the gain we are primarily interested in with regard to audio amplifiers. The gain previously calculated was the DC gain, which was numerically identical to the AC gain, but since the amplifier was decoupled from the preceding stage with a capacitor, there was no DC applied to the transistor other than that provided by the bias network, which set the standing current to 1mA and the output voltage to 10V. DC gain and offset is important, because a decoupling cap can be avoided in some cases, but not here.

In the earlier post the gain was stated to be R[SIZE="1"]C[/SIZE]/R[SIZE="1"]E[/SIZE]. This was a simplification, and, more strictly the gain is R[SIZE="1"]C[/SIZE]/(R[SIZE="1"]E[/SIZE]...
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Old

Further education...

Posted 8th September 2010 at 02:35 PM by chris661

Well, this is a first. A blog.

Second day of college (6th form, etc), and all seems to be going well. The teacher seem reasonable enough, even though they do seem to like going back to basics. I expect that will change when the course is properly underway.

I'm taking AS level (A-level comes next year) Physics, Mathematics, Biology and Chemistry, with the intent to go into either a medical career, or to become an engineer of some kind (maybe work for B&W, Celestion or KEF........). Anyway.

What was I up to? Oh yes, changes that will undoubtedly take place. I really, sincerely hope that the teachers will stop telling everyone how much of a step up AS level is from GCSE, and actually do some teaching!! We were warned at the open evenings, in the introductory speech by the principal, by our secondary school teachers, even our parents, friends etc that have been through the experience.

Right. That's got that out of the way. Now...
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Old

100-160w mosfet amp

Posted 7th September 2010 at 08:30 PM by johnalexwarren

This is my first serious amp project. It uses the IRFP9240 & IRFP240 MOSFETs and delivers 100WRMS into 8Ω or 160WRMS into 4Ω at 0.1% THD.

Many thanks go to Edwin Paij @ AED (http://users.swing.be/edwinpaij/welcome.htm) for the design .

I have now gathered the majority of components and am currently active in the forum looking into PSU design...
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Old

Turntable Technics SL-3 Wiring Diagram wanted

Posted 6th September 2010 at 04:45 PM by SirErik

Hey, I've got my Technics SL-3 turntable power supply damaged by a high voltage burst from the power station. I've found out that the transformator is damaged, but I haven't been able to find a new one. The number on it is SLT48DT 15E. I need to know either where to buy a new transformator or what specifications (voltage 240/? . .) this transformator has. Anyone who can help me solve this problem?
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Old

LME49830 based amp

Posted 4th September 2010 at 07:02 PM by alexcp (My DIY projects)
Updated 8th October 2012 at 11:26 AM by alexcp

This is an implementation of National's reference design for LME49830 with two matched pairs of 2SK1530+2SJ201 per channel. The PCBs were made using National's gerbers (thus National's logos). Sounds surpisingly good, but it has just been completed; I did not have a chance to listen to it carefully yet.

Update: I rebuilt the amp as a pair of monoblocks, each delivering healthy 200W into 8 ohms. It now looks tidier.

Update: the original Gerbers from National are nowhere to be found since national.com was merged into ti.com. Attached are the original archives downloaded from the national.com.
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Old

YAGC (Yet Another GainClone)

Posted 4th September 2010 at 06:58 PM by alexcp (My DIY projects)
Updated 5th September 2010 at 08:59 PM by alexcp

This was unavoidable, I guess. Dual mono LM3886 kit from ChipAmp.com with Avel Lindberg's transformers in a wonderfully compact enclosure from Design Build Listen. I liked the simplicity but not the sound. Why is everyone so excited with gainclones? IMHO, Papa's Zen V4 is not much more complicated to build (although no kit is available), but is so much more an interesting experience!
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Old

Lm60 from AmpsLAB

Posted 4th September 2010 at 06:54 PM by alexcp (My DIY projects)
Updated 7th July 2011 at 01:33 AM by alexcp

Last year I got an Lm60 kit from AmpsLAB. This year, I finally got an enclosure from Design Build Listen and a power supply and built it. Each channel is built on a small (120x60mm) one-sided PCB and uses one 2SK1058+2SJ162 pair in the output stage. With proper biasing, the sound is good, esp. for such a simple and compact design. I should have started with this one, rather than with the (equally inexpensive) K-8LS.
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Old

Yet Another Distraction...

Posted 31st August 2010 at 11:44 AM by wintermute (Wintermutes Rantings)

Well I said no more excuses, and I for the most part started to make some progress. But good old Murphy stepped in and threw a spanner in the works.

The Boot Drive on my main computer decided to die on me, I've got backups of all the important stuff so no big deal other than the inconvenience. I could always use my work laptop... step in Murphy again, it too decided to die... once again have backups but all of a sudden nothing to run LT spice on, bring up my Plans, test data or anything.. I've got a loan one but I'm not going to set it up for a couple of weeks only.

So since my main computer was nearly 8 years old (single core Athlon 2000 which is really only 1667Mhz) I decided an upgrade was in order... This would probably have been a relatively modest machine if it weren't for my recent discovery of LTSpice and the knowledge that it takes a lot of cpu grunt, and that it benefits from multiple cores!!

So What have I been doing? Not working...
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Old

How low can you go? - part II

Posted 31st August 2010 at 04:34 AM by abraxalito
Updated 1st September 2010 at 05:23 AM by abraxalito

Here are the schematics - the original output stage and the modified one.

On the first player I bought, I did all those mods in one hit. The third pic shows what they looked like - I took out some of the redundant connectors (guessing the same board is used in players which have more features like component video outputs) to make space for the electrolytics. Having replaced the board (just two screws, one on the rear and another in the base), then I listened. The improvement in bass performance brought about by increasing the value of the coupling caps was noticeable in listening - the cello became more full-bodied - and also on a frequency response plot I made using Audacity. I felt (but can't quite describe) that the soundstaging has improved - music feels more interesting to listen to somehow. I week or so later, I went out and bought a second one (at 99RMB, who's counting?) to remind myself of the original sound. On listening for the first time to a CD I'd just bought...
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