tda2050 pcb available from maplin soon

[scaesic]

http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=220055&doy=14m10

i've been waiting for this one for about 6 months, the website says it will be in stock next week, finally...

[smnm]

What have you got in mind for it? Just curious.
Obviously an amp, but what voltage will you be using it at? The datasheet says it's a hifi power amp - is it good for guitar?

[scaesic]

it's just a power amp thatl drive a speaker, its not necessarily a hifi amp. I am planning to use it with a tone section taken from a polytone amp, and the mosfet boost as a pre.

Should be providing it around abouts 40v DC, perhaps slightly less.

[John Lyons]

Keep in mind that that TDA2050  kit is a hifi level -10 db kit with a low input impedance.
If you look up the data sheet you can make it yourself for much cheaper.

The kit looks to be straight off the datasheet.
Marty mart posted an amplifier build with the TDA2050 and his mods to it.
Basically just altering the input impedance and adding a volume control.
Search for it.

John

[smnm]

Thanks - I've been thinking abour building the ROG Supro amp sim for a while - I'll look into combining them = winter project!

I have a 70s SS Vox amp that I use for convenience quite a lot, but it doesn't sound great and has major hum issues, so I could do with another small-ish light amp.
I've been busy at work lately, but this will quieten down in December.

[MartyMart]

Here's the thread with photo's and mp3 .... schematic is halfway down page 1
http://www.diystompboxes.com/smfforum/index.php?topic=57018.0

I have not gone back to build a dual powered version yet, still have my Park traffo hanging around.
Even with a single 18v supply, it's a pretty impressive 10 watt practice amp and VERY easy to build.
Marty.

[scaesic]

Keep in mind that that TDA2050  kit is a hifi level -10 db kit with a low input impedance.
If you look up the data sheet you can make it yourself for much cheaper.

The kit looks to be straight off the datasheet.
Marty mart posted an amplifier build with the TDA2050 and his mods to it.
Basically just altering the input impedance and adding a volume control.
Search for it.

John

it doesnt matter about impedence as i'm not putting the guitar straight into it, its going into a pre/tonestack first. Also, where does it say its -10db?

[John Lyons]

All home CD/tape deck etc etc devices are -10db level ouputs as are the inputs to most home units.
I'm not 100% sure but I'd imagine that this is the case... I could be wrong.

John

[scaesic]

theres a closed loop gain of about 30db according to the data sheet

[John Lyons]

-10db is a standard home audio level reference.  30db is the gain of the amp. Two different things.
At any rate, check out martymarts post and you can see how he upped the input impedance compared to the datasheet.
You can either build one from scratch with the guitar friendly impedance or mod/alter the stock unit.

John

[scaesic]

-10db is a standard home audio level reference.  30db is the gain of the amp. Two different things.
At any rate, check out martymarts post and you can see how he upped the input impedance compared to the datasheet.
You can either build one from scratch with the guitar friendly impedance or mod/alter the stock unit.

John

but the tda2050 is "seeing" the output of the mosfet boost/tonestack w/ opamp output buffer, not a guitar pickup.

do i still need to change the impedence?

surely the mosfetboost will bring the guitar up to -10db ballpark too?

[scaesic]

-10db is a standard home audio level reference.  30db is the gain of the amp. Two different things.
At any rate, check out martymarts post and you can see how he upped the input impedance compared to the datasheet.
You can either build one from scratch with the guitar friendly impedance or mod/alter the stock unit.

John

-10db ~ 0.35v

mosfet boost gain = 1.5 - 56, typical guitar voltage = 0.1v

so output of mosfet is 0.15v min , 5.6v max.

[tasos]

Keep in mind that that TDA2050  kit is a hifi level -10 db kit with a low input impedance.
If you look up the data sheet you can make it yourself for much cheaper.

The kit looks to be straight off the datasheet.
Marty mart posted an amplifier build with the TDA2050 and his mods to it.
Basically just altering the input impedance and adding a volume control.
Search for it.

John

what should the input impedance be?[value of the resistor please? ]i am planing on using it for bass or mic...