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LME49810 300 W amp kit from TaoBao (Test)

Posted 5th September 2011 at 11:17 PM by panson_hk

The board is ready for test. The bias level is adjusted via monitoring the THD level as well as the distortion residual.

THD vs power for 20 Hz, 1 k and 20 k for 8 Ohm are shown in the figure. It is so high compared to all my 498xx amps. For 1 k, we should have THD lower than 0.0008 %.

Let test the THD vs power without load. Without load connected, output stage contributes very little distortion. This can be used to check whether the 49810 functions as spec or not.
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LME49810 300 W amp kit from TaoBao (Cont.)

Posted 5th September 2011 at 01:10 PM by panson_hk

The amp is assembled and ready for testing. It is designed to have two rails: one for LME49810 (suggested +/- 60 V) and one for driver/output (suggested for +/- 45V). The speaker protector uPC1237 also has an input for detecting the presence of AC (half-wave rectified).

In my initial test, one rails supply to 49810 and the output stage. The positive is also connected to the AC input of upC1237.
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LME49810 300 W amp kit from TaoBao

Posted 5th September 2011 at 09:26 AM by panson_hk
Updated 5th September 2011 at 09:36 AM by panson_hk

This kit is available in many sellers in eBay and TaoBao. My one is purchased from TaoBao. The output stage does not have protection. All the resistors are pre-inserted. What a nice service to save some time.

The 49810 heatsink screw holes are not aligned well. I also worry about its size.

The Miller compensation cap is a pre-soldered chip cap on the bottom side as shown in the picture. Fuses are pre-installed in the fuse holders.

Output are five pairs of 5200/1943.
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Old Majestic Car Amp

Posted 2nd September 2011 at 02:00 AM by DigitalJunkie

I got this amp in 'fried' condition from a friend many years ago. I finally managed to get it working,and I've been using it for my subwoofer amp ever since,probably about 10 years now? It's not the greatest amp,but it has served me very well on sub duty.

It claims to be 200W per channel, and bridgeable to 400W. It might even pull that off,on a good day.

Anyways,I had some very poor scans of the schematic for this amp(which I later discovered was almost identical to a 4 channel Rockwood amp.) I managed to re-draw the basics,and thought I'd post it up for the forum to check out.

I've been thinking of taking this amp to the bench to do some tests,and maybe some tweaks. I'm all ears if anyone has any thoughts?

Here's a link to the redrawn schematics,I might put the original scans in there also.
Some component values are missing,I was going from memory,and what I could make out from the original scans.

MA-9400 pictures by Nothing40 - Photobucket
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EMT 950 Turntable

Posted 31st August 2011 at 05:00 AM by Davo58

Has anybody had to try and play discs that run at slower speeds than 33 rpm.
We have some 24 rpm and 16 rpm discs that we need to digitise and was wondering if you hve been able to slow down your EMT950 to be able to do this.
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Please help to decide box for FE103En

Posted 29th August 2011 at 09:54 PM by audiomovil

i want to build a box for my new FE103En, please help to decide between Buschhorn Mark II or the Sperrin and Vampyr-v, from Woden Design.
I use a Yamaha amplified 10" sub and Yamaha amp 60x2, for use in a living room 11 ft by 13 ft, for movies and music., jazz and rock.
Thanks for the help.
Gustavo Espino from Jalisco México.
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Best source for TX2575 Naked Z-Foil Resistor

Posted 28th August 2011 at 08:52 AM by dvb projekt
Updated 28th July 2014 at 11:12 AM by dvb projekt

All members who want to use the "holy grail" audio resistor,

the TX2575 Naked Z-Foil,

could order it direct at Texas Components.


That´s the cheapest way to get it IMO.

They have also great Trimpots with Bulk Metal Foil Technologie.





P.S.: If you send a mail to Arbie, send her regards from me!
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Conn strobotuner

Posted 27th August 2011 at 02:17 AM by blackveilbridessixx

does anyone know how much a conn strobotuner model st 11 is worth?
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Projection lens and Fresnel lens

Posted 23rd August 2011 at 12:37 PM by djhot143

Hi to all friends,I am new here.
My name is DHIRAJ from mumbai,india.

I need your help, I want to make a projector but i am not getting parts of it.
Can anyone tell me where i can buy projection lens and Fresnel lens in Mumbai. plz help me.
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Rating: 2 votes, 4.00 average.

TDA1541A DAC Module V3.0 - Out of production

Posted 20th August 2011 at 09:32 AM by dvb projekt
Updated 30th November 2016 at 10:25 AM by dvb projekt

The Red Baron

aka TDA1541A DAC V3.0

Click the image to open in full size.


The evolution brings the following changes

- Direct shunt voltage inputs with shortest onboard traces
- I2S In-/Outputs with shortest onboard traces
- Upgrades DEM Synchronizer
- Onboard Grounded-Gate MOSFET Current Buffer I/V Stage
(-ecdesigns- MK7 version)
- Compacter design


Still on the module

- Separate GND-Trace for DEM-Synchroinizer
- Master/Slave connectors for parallel DAC module usage
and external I/V Buffer stages e.g.
Tube-I-zator & DDNF Stage
- Groundplane
- no SMD Design

Click the image to open in full size.


The PCB has the following data:

Material: FR4 - 2mm
Layers: 2
Board size: 125x73 mm
...
Attached Files
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File Type: pdf The Red Baron DAC.pdf (28.9 KB, 2174 views)
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