| fity |
I am a madman of the audio,
Can somebody help me or to say me if this design has good guys proven to be?
Has somebody constructed it?
I need slight knowledge to construct also the power supply, he has a consumption of 5A
Can somebody help me?
(copyrighted attachment deleted by moderators) |
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| lineup |
| quote: | Studio 350 - High Power Amplifier Kit
Ref: Silicon Chip Jan/Feb 2004.
This fantastic new amplifier kit will deliver 200WRMS into a 8Ω load, or 350WRMS into a 4Ω load. It is super quiet, with a signal to noise ratio of -125dB(A) at full 8Ω power. Harmonic distortion is a fantastic 0.002%, and frequency response is almost flat between 15Hz and 60kHz. Kit supplied with PCB and all electronic components. |
SC = Silicon Chip
If you can get the PCB it would be easy to build.
Notice Q7, Q8 and Q9 is on heatsink.
If you can not find BF469/470 you can replace with MJE340/350.
I think is a good amplifier, and should be safe to build.
This Kit is being sold at several websites.
Silicon Chip homepage in Australia has info and instructions for building:
http://www.siliconchip.com.au/cms/A_100503/article.html
http://www.siliconchip.com.au/cms/A_100618/article.html
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| lineup |
for the power supply
which is +-70 Volt DC
You need 2 transformers: 50V+50V 500VA
Parts list:
Power supply - for one channel
------------------------------------
50V+50V 500VA toroidal mains transformer (Altronics Cat. M-5750)
35A 400V chassis-mount bridge rectifier
6 8000uF 75V chassis-mount electrolytic capacitors (Altronics Cat. R-6722)
2 470nF 100V MKT polyester capacitors
4 15kOhm 1W resistors |
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| quasi |
This design is based on a well proven topology that has been around for 20 years or so. Improvements over time have been the availability of better semiconductors and a better PCB layout (which impacts the sound).
Overall it is an excellent design and should provide great satisfaction. Be aware though of the total project price, if you had to buy everything new I doubt there would be much change out of $1,000 US. It might even cost more depending on your choice of components & case.
Cheers |
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| mastertech |
These guys (sc) design for low distortion, yes the design is typical
of theirs over the years they have stuck with pury much std topologies of low dist., yet this design doesnt go as far into their
philosophy quasi prety much has said it all, i am sceptical about
its sonic impact however
thank you guys for sharing
Regards |
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| PM650 |
This is a bit off topic, but I would be curious to know anyones comments on this amp schem compared to the Studio 350:
http://www.mustangmods.com/data/2197/amp_schematic.jpg
The reason I'm asking is the amp can be purchased in kit form very cheap ($30) with heatsink, and it seems to be similar to the 350 at a glance. |
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| lineup |
| quote: | Originally posted by PM650
This is a bit off topic, but I would be curious to know anyones comments on this amp schem compared to the Studio 350:
http://www.mustangmods.com/data/2197/amp_schematic.jpg
The reason I'm asking is the amp can be purchased in kit form very cheap ($30) with heatsink, and it seems to be similar to the 350 at a glance. |
... it seems to be similiar ...
Yes, really.
So many components are identical, that the one making this
has used the Studio 350 schematic and changed a few things.
Or the other way around.
Main difference is this has only 1 output pair and 60V supply = lower power.
This one has a current/power limiter for protection.
A few other small details also are different.
But this is 'same' amplifier. |
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| PM650 |
| Well, I'm glad to hear this lineup. I constructed my first amplifier using a pair of these so I guess my cheapness didnt get the best of me, for once. :) |
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| quasi |
This schematic is a direct copy from one published by Electronics Australia Magazine in 1989 (or maybe they copied it) with only a couple of minor changes. One change that I would reverse is feedback resistor R12, this was originally 1K. This will set the gain to 27. As it stands the amplifier has too much gain (48) and will perform better with a gain of 27.
The output stage (2SC5200 / 2SA1943) is not strong enough for 50 volt rails, and at high volumes a 4 ohm load would surely blow them. It does have over-current protection, but this seems to be configured for stronger transistors.
But if the kit includes a heatsink, a pcb and all the components, it's a steal. Even if you upgraded the output transistors it is still great value.
Cheers |
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| fity |
can i change the 8000uf caps and to put 10000uf 100v?
i not find the 8000 uf value |
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| lineup |
| quote: | Originally posted by fity
can i change the 8000uf caps and to put 10000uf 100v?
if not find the 8000 uf value |
Sure you can.
80 or 100 Volt is better margin. 75V is only 5 Volt safety margin to 70 V.
3x8.000uF is 24.000uF to +70V and same to -70
It might be possible to replace those 3 with one 22.000uF/100V.
But better to make it 3x10.000uF = 30.000uF
and same to negative.
It is better in this case to take a bit more than 24.000uF.
And also better to use 100V capacitors. |
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| jmateus |
Hi folks
I recently built 2 versions of the studio 350 and I am very, very
happy with the results.
First one is a subwoofer amplifier made with only 3 pairs of
outputs and supplied with +-59 volts. Great sub amp!
The second one is a stereo amplifier again with only 3 pairs
of outputs, I would not need 350 W so the option. This design
is so reliable that it works at first try provided you take caution
on the requisite to adjust bias when first turned on.
I built the two versions from scratch so I didn't spend much
money on them having most of the parts around.
In both versions I used MJL3281A/MJL1302A that are beefier
transistors, 200V/15A.
One recommendation though, do not use TO3 transistors
MJ 15003/15004 from OnSemi, these are not the best transistors
for this type of amplifier (and not for any amplifier, anyway)
they are stronger 2N3055/2955 which are outdated.
You can't go wrong with this design. |
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| lineup |
| quote: | Originally posted by jmateus
Hi folks
I recently built 2 versions of the studio 350 and I am very, very
happy with the results.
.....
You can't go wrong with this design. |
Yes, it looks like a serious amplifier.
A lot of work has been done to trim and tweak this amp.
Here is PCB layout for those interested.
As PDF, or as zipped EPS file.
Studio 350 PCB (PDF)
Zipped EPS |
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| quasi |
| Umm...what do you call it when you re-produce something really well .......umm oh that's it ....it's called Copyright. |
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| edl |
| quote: | Originally posted by PM650
This is a bit off topic, but I would be curious to know anyones comments on this amp schem compared to the Studio 350:
http://www.mustangmods.com/data/2197/amp_schematic.jpg
The reason I'm asking is the amp can be purchased in kit form very cheap ($30) with heatsink, and it seems to be similar to the 350 at a glance. |
Dear PM650,
a better realization attached.
Best regards, |
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| lineup |
| quote: | Originally posted by quasi
This schematic is a direct copy from one published by Electronics Australia Magazine in 1989 (or maybe they copied it)
.........
Originally posted by lineup
A lot of work has been done to trim and tweak this amp.
.........
Originally posted by quasi
Umm...
what do you call it when you re-produce something really well
.......umm oh that's it ....it's called Copyright. |
Most work to trim and tweak was obviously done in 1989.
Silicon Chip two articles was in 2004, published by 2 authors.
As Silicon Chip and Electronics Australia Magazine both are magazines from Australia,
I guess eventual copyright has been cleared. |
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| destroyer X |
And despite all efforts i made to make it better, it was dismounted considered not enougth good.
My personal, subjective, individual, point of view...the truth, only asking God personally.
I am telling about ,this one, i am showing you.
regards,
Carlos |
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| destroyer X |
make it sounding nice.
I could not make it sound good.
Here, you can see that i tried hard...but no results!
regards,
Carlos |
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| jacco vermeulen |
Carlos,
should the A1215 in your schematic not be A1216 instead ?
| quote: | | (and not for any amplifier, anyway) |
Very drole !
Andalucia, la parte mas bonita de Espana. |
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| destroyer X |
Me gusta mas la Lucia que anda....es mejor que Andalucia.
I prefer Miss Lucia, the one that can walk ...she is better than a stone and concrete town as Andaluzia , Andalucia (Walk Lucy).
regard,
Carlos |
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| elementx |
| Does anyone have a PCB available? Or at least the artwork to make one? |
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| edl |
| quote: | Originally posted by edl
Dear PM650,
a better realization attached.
Best regards, |
Fully version attached,
200W-RMS/4ohm, d<0,1%, 10Hz-30KHz |
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| quasi |
| quote: | Originally posted by lineup
Most work to trim and tweak was obviously done in 1989.
Silicon Chip two articles was in 2004, published by 2 authors.
As Silicon Chip and Electronics Australia Magazine both are magazines from Australia,
I guess eventual copyright has been cleared. |
Aaaah back from fishing.
I was talking about posting the artwork layouts froom the website. The SC layouts are indeed copyright.
The fish & squid & crabs were delicious. |
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| edl |
| quote: | Originally posted by PM650
This is a bit off topic, but I would be curious to know anyones comments on this amp schem compared to the Studio 350:
http://www.mustangmods.com/data/2197/amp_schematic.jpg
The reason I'm asking is the amp can be purchased in kit form very cheap ($30) with heatsink, and it seems to be similar to the 350 at a glance. |
Hi,
Let's buy the kitset, and upgrade that this way.
The offset circut can be cancelled, if the DC-offset in the output isn't bigger than +/-100mV.
It will give you 200W-RMS on 4ohm.
Regards, |
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| mikeks |
| Deeply compromised design...:bawling: |
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| darkfenriz |
| Carlos, what are you doing for this baby? |
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| yugaaa |
| could anyone post the schematic and the parts list ? |
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| AKSA |
Has anyone seen Carlos/Destroyer?
We all miss him.......
Hugh |
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| edl |
| quote: | Originally posted by mikeks
Deeply compromised design...:bawling: |
Yeah, I know it, but it designed for PA, and I wanted to keep it simple, using easly available parts.
Regards, |
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| microchip |
hello edl this is Klaus i think your circuit is really nice i like the
way you adjust dc-offset, off the critical areas (some ppl think so)if your calculations are correct it would sound really good too
Regards
Klaus PH.d |
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| edl |
Hi,
the amp is firstly designed for MJ15003/MJ15004 output transistors. If I use 2SC5200/2SA1943, the currents could be lower, because the 2sc/2sa pair has higher gain.
Anyway the circut works fine with 2sa/2sc outputs too, but 2×12mA current in the second diffamp is unnecessary. We can use only for example 2×6mA, and than the MJE340/350 transistors shouldn't be heatsinked.
This design is not the state of art, but as I wrote, for PA purpouse its enough.
But we can keep the currents higher, with heatsinked MJE trans'. Higher current here means better quality.
If the offset isn't bigger than +/-100mV (in the most cases it not higher, but I don't matching the transistors, so it can be), the 100k resistor (that goes from the offset-circut to the input) need to be eliminated, because offset adjust is unnecessary.
Regards, |
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| idealist2002 |
Hi,
Can i use anther output transistors for the SC 350? i have 4 pairs Mj15024 / Mj15025 mounted in a DIY Case.
:D |
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| sakis |
seen this studio 350 and since i like so much simple constructions i wonder if i can get any more information specified about this amp .....
i ve been reading the post through ....and my applications are small pa application where power stability and capabilty on working 100% of power for many hours is the target ( often above quality )
supposed that the rest of the construction is perfect (proper trafo , caps , softstarts cooling ,ground loops and goes on ) is correct do you recoment this amp to my applications ???
thank you sakis.... |
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| sakis |
to edl
sorry but looking at the post ....i dont get it ( ????) the 200w 2 4R is the power of the studio 350......?????
cause if it is its a joke
or is it the power of this other schematic ????? |
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| sandyK |
The Studio 350 is 200W/Ch. 8 ohms and 350W/Ch. 4 ohms
Electronics Australia no longer exists. EA copyright is now owned by Silicon Chip, who also have their back issue articles.
The Studio 350 is streets ahead of those old EA designs.
Carlos, surely you are joking about any modern amplifier with any pretensions to quality, using those slow and antiquated 2N3055/2N2955 ?
Regards
Sandyk |
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