Hi, I'm going to put together a TDA2050 audio amp using a single ended supply rather than split rail however I'm confused about how much voltage I can power it with.
The datasheet states the supply voltage can be +/-25v so does that mean I can have upto 50v with a single ended supply or am I limited to +25v effectively halving the output power?
Datasheet:
http://www.st.com/content/ccc/resource/technical/document/datasheet/1d/71/14/1e/5d/cf/47/01/CD00000131.pdf/files/CD00000131.pdf/jcr:content/translations/en.CD00000131.pdf
The attached image shows the configuration I will be using.
Thanks.
The datasheet states the supply voltage can be +/-25v so does that mean I can have upto 50v with a single ended supply or am I limited to +25v effectively halving the output power?
Datasheet:
http://www.st.com/content/ccc/resource/technical/document/datasheet/1d/71/14/1e/5d/cf/47/01/CD00000131.pdf/files/CD00000131.pdf/jcr:content/translations/en.CD00000131.pdf
The attached image shows the configuration I will be using.
Thanks.
Attachments
+/- 25V or +50V is the absolute maximum.
But yes, you could run with a single supply of +50V.
Not really recommended though.
The data sheet "suggests" +/- 18 to +/- 22.5 for 8R and 4R loads, which would be 36V to 45V single supply.
Have fun.
But yes, you could run with a single supply of +50V.
Not really recommended though.
The data sheet "suggests" +/- 18 to +/- 22.5 for 8R and 4R loads, which would be 36V to 45V single supply.
Have fun.
Thanks. Oh I know that is just the absolute maximum before it goes pop but I just wanted to make sure before I go connecting it to a single supply.
So the +/-25v ratings are definitely not for each of the output transistors and it can take a single supply of 40v or so? Its just I've been doing some googling and some people have said 25v is the maximum for single supply whilst have stated the opposite which can get confusing for someone like me who's only experienced single supply chip amps before.
So the +/-25v ratings are definitely not for each of the output transistors and it can take a single supply of 40v or so? Its just I've been doing some googling and some people have said 25v is the maximum for single supply whilst have stated the opposite which can get confusing for someone like me who's only experienced single supply chip amps before.
if you are planning to purchase them now...
i got a bad news.
100% (according to me) that they are fake, and i woul not run them above +- 15 volts for any load, or a single supply of 30 volts...
i got a bad news.
100% (according to me) that they are fake, and i woul not run them above +- 15 volts for any load, or a single supply of 30 volts...
TDA2050 used in Vox VT30 running at +/- 18v
I just repaired one where the TDA2050 had failed at those voltages so don't push it
I just repaired one where the TDA2050 had failed at those voltages so don't push it
I got them from Maplin which is the radioshack of the UK a few years back so I assume they should be good, I know they sell some tat there but I don't think they would sell counterfeit chips.
I was hoping to power them with 2x 12v SLA batteries in series for 24v nominal, but might be closer to 26.5v when fresh off the charger.
I know better chips exist for this purpose but this is more of a spare parts build anyway.
I was hoping to power them with 2x 12v SLA batteries in series for 24v nominal, but might be closer to 26.5v when fresh off the charger.
I know better chips exist for this purpose but this is more of a spare parts build anyway.
Dam, any idea why it failed? I don't intend on throwing any party's with this thing so 10w of clean power and i'll be happy.
Would that +/-18v be the same as 36v when single ended?
My actual specimen or the chip in general? If the latter its just a standard 5 pin TO-220 part.
They should stand 36V, even more 24/26V with no problems.
Yes, the VOX one failed, no doubt, that´s why Servicing exists, a few will fail , most (as in >90/95%) will happily live for years.
We Techs tend to see the problem cases, by definition.
Main problem with TDA2050 is that they are no longer made, shelves emptied quickly and now many sell relabelled TDA2030 which *are* still being made.
Which are excellent, simply stand less voltage.
If you "think TDA2030" you will have no problem.
Naked TDA2030 on left, TDA2050 on the right.
Now you know why one happily handles twice as much as the other:
A better option is LM1875, which is still being made.
Yes, the VOX one failed, no doubt, that´s why Servicing exists, a few will fail , most (as in >90/95%) will happily live for years.
We Techs tend to see the problem cases, by definition.
Main problem with TDA2050 is that they are no longer made, shelves emptied quickly and now many sell relabelled TDA2030 which *are* still being made.
Which are excellent, simply stand less voltage.
If you "think TDA2030" you will have no problem.
Naked TDA2030 on left, TDA2050 on the right.
Now you know why one happily handles twice as much as the other:
An externally hosted image should be here but it was not working when we last tested it.
A better option is LM1875, which is still being made.
absolute maximum voltage is stated as ±25Vdc
That's where the 50V comes from.
Your chip must never exceed 50V rail to rail, even when the mains is at maximum tolerance.
That means your normal MAXIMUM is about ±22Vdc and you get that from a 15-0-15Vac transformer.
But you could use a 9-0-9Vac, or 10-0-10Vac, or 12-0-12Vac transformer.
When you halve the supply voltage you very roughly get one quarter of the maximum power output.
From the rule: P=IV=I²R=V²/R
That's where the 50V comes from.
Your chip must never exceed 50V rail to rail, even when the mains is at maximum tolerance.
That means your normal MAXIMUM is about ±22Vdc and you get that from a 15-0-15Vac transformer.
But you could use a 9-0-9Vac, or 10-0-10Vac, or 12-0-12Vac transformer.
When you halve the supply voltage you very roughly get one quarter of the maximum power output.
From the rule: P=IV=I²R=V²/R
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That's sneaky of them but I think maplin should be safe (fingers crossed).
Yeah, its funny because some of the most robust transistors I've purchased have been from maplin. I've got some 2n3055's that have been abused to the extreme but they haven't failed yet.
Hi, I don't have any suitable split rail transformers laying around and since this is a spare parts project I'm just trying to make use of what I have without spending any money. Would a single +36v supply be ok? like I said I'm not running this chip with separate plus and minus rails.
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Ah that's great I'll go for that then.
Secondly just another quick question, what gain is a good starting point? I'm going to be driving it with a laptop and phone headphone output.
Both of my previous chip amp builds lm386 and la4705 had gains of around 40db IIRC and that seemed ok with a volume pot, is that a good value to aim for when paired with headphone jacks?
Thanks.
> what gain
Collect clues.
36V total supply, divided by 2.828, by finger, is 12Vrms output.
Cellphones use 3V batteries. You-would-think they could do 1V output. But there is a chart running around which shows some as high as 1+V, and others apparently programmed not to exceed 0.24V.
12V/0.24V is gain of 50. Your volume knob covers the higher-output phones.
Collect clues.
36V total supply, divided by 2.828, by finger, is 12Vrms output.
Cellphones use 3V batteries. You-would-think they could do 1V output. But there is a chart running around which shows some as high as 1+V, and others apparently programmed not to exceed 0.24V.
12V/0.24V is gain of 50. Your volume knob covers the higher-output phones.
The recommended values in the data sheet are a good starting point coming in at around 30db. You can go higher without much concern, lower could see stability issues.
The values look about right for accepting a line level input.
The values look about right for accepting a line level input.
No idea why failed, could be overstress, manufacturing fault.......
Remember these were intended for domestic amplifier use, it's just that Guitar Amp designers saw a low cost opportunity to put into their cheaply made in China etc. products & sell at inflated prices to Yoof who wander into Music stores having seen Vox & Marshall logos on Top of the Pops 😀
Many years ago when I was a service tech and we used to replace TDA2030's (no TDA2050's back then) by the bucket load. They were used in all sorts of cheapo audio systems and certain horrible TV/Audio tower combinations. Somehow the customers managed to get them to go up in smoke.
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