My amplifier Using Tube buffer and LM1875

Luck · 28th July 2006, 07:57 AM

Hi,All
I made my new amplifier with tube 6922EH as the input buffer,

2*LM1875 for the power ouput.It sounds nice, i think output power is not the first place but the quality of the sound is.

Here are some pictures.....Cheers........

Luck · 28th July 2006, 08:45 AM

front view, it's made of wood.....

juma · 28th July 2006, 09:23 AM

Great job Luck !
Try to replace that bridge with MUR860 / MUR820 / MUR840. It will give you nice improvement in upper mids and highs (the difference is most obvious there).

Keep up the good work!

Cheers !

Luck · 28th July 2006, 09:29 AM

Many thanks for your suggestion. i will try ....

zatramusic · 28th July 2006, 01:13 PM

great job..impressive

i've too recenlty made some boards for the little fella

Luck · 29th July 2006, 02:36 AM

Hi,zatramusic, your PCB is so small. How about the voltage of your PCB?? Here are some pictures of my ECC88+LM1875 PCB,
being soldering now. I use 20V----0----20V AC , 150W transformer for power supply. The PCB is draw by protel.Including
the time delay part when power on.

Luck · 29th July 2006, 02:41 AM

another picture of the PCB, the ic and relay will be soldered soon.

zatramusic · 29th July 2006, 09:29 AM

hi Luck, i will use 2x18V 60VA per channel...
...the board is about 50x50mm and it's doublesided
..and they are made with eagle

your pcb's are far more complexed than mine..i wanted to stay minimal:
chip
8 diodes
3 resistors
2 capacitors

here's a picture

and another one

Luck · 30th July 2006, 03:38 AM

Hi,zatramusic, i can only see two resistors in your PCB,where is the left one? can you show me a picture including your transformer? it is suggest to put two caps with value 100nF close to LM1875.
Concerning my pcb ,it seems a little complexed. The IC that i use are : LM1875 for power output, LM7812 for the relay part, LM7806 for heating the lamp inside the tube.
Tomorrow i will finish all the soldering, then i will show you a picture....

Cheers...........

zatramusic · 30th July 2006, 08:28 AM

Hi Luck..
I've borowed my camera yesterday :/
The third resistror is on the other side of the pcb and the caps are 1000/50v...they are less then 20mm from the chip so it's ok

i used a toroidal transformer from http://www.toroidy.pl (a polish company)

bests

zatramusic

ps..as soon as i get my camera i will post some pics

28th July 2006, 09:29 AM	#4
Luck diyAudio Member Join Date: Jul 2006	THANKS JUMA Many thanks for your suggestion. i will try ....

30th July 2006, 03:38 AM	#9
Luck diyAudio Member Join Date: Jul 2006	Hi,zatramusic Hi,zatramusic, i can only see two resistors in your PCB,where is the left one? can you show me a picture including your transformer? it is suggest to put two caps with value 100nF close to LM1875. Concerning my pcb ,it seems a little complexed. The IC that i use are : LM1875 for power output, LM7812 for the relay part, LM7806 for heating the lamp inside the tube. Tomorrow i will finish all the soldering, then i will show you a picture.... Cheers...........

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Beginner's Gainclone, HiFi LM1875, The Amplifier Board	danielwritesbac	Chip Amps	84	15th January 2010 10:44 PM
compact lm1875 amplifier	Jamh	Chip Amps	9	25th August 2009 12:50 AM
Tube buffer before pre-amp/amp?	Destroyer OS.	Instruments and Amps	2	9th January 2009 07:09 PM
Tube Buffer IGC - need help ....	Will	Chip Amps	22	21st November 2003 07:54 AM
Tube buffer	NickC	Tubes / Valves	3	9th May 2002 11:20 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

28th July 2006, 09:23 AM	#3
juma diyAudio Member Join Date: Nov 2005 Location: Zemun	Great job Luck ! Try to replace that bridge with MUR860 / MUR820 / MUR840. It will give you nice improvement in upper mids and highs (the difference is most obvious there). Keep up the good work! Cheers !

28th July 2006, 01:13 PM	#5
zatramusic diyAudio Member Join Date: Dec 2005 Location: Wroc³aw	great job..impressive i've too recenlty made some boards for the little fella

29th July 2006, 09:29 AM	#8
zatramusic diyAudio Member Join Date: Dec 2005 Location: Wroc³aw	hi Luck, i will use 2x18V 60VA per channel... ...the board is about 50x50mm and it's doublesided ..and they are made with eagle your pcb's are far more complexed than mine..i wanted to stay minimal: chip 8 diodes 3 resistors 2 capacitors here's a picture and another one

30th July 2006, 08:28 AM	#10
zatramusic diyAudio Member Join Date: Dec 2005 Location: Wroc³aw	Hi Luck.. I've borowed my camera yesterday :/ The third resistror is on the other side of the pcb and the caps are 1000/50v...they are less then 20mm from the chip so it's ok i used a toroidal transformer from http://www.toroidy.pl (a polish company) bests zatramusic ps..as soon as i get my camera i will post some pics

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)