Audiodoc
Well-Known Member
Looks fine. Try powering with a bulb tester using test speakers. Check DC at output.
I've 2200uf x 2 per amp pcb and 10,000uf x 2 on rectifier pcb
capacitor bank per rail, is it the no. of capacitors on power suppy or capacitors on amp pcb or a total of both?
It plays fine at 50% volume but the SPL sags at 80% after a couple of minutes.
When I check DC at the speaker binding posts I get 70 mv & 116 mv on left and right channel respectively.
OK, so an output rated at 6 0 6v with 1A will become 0 12v 500Ma
Also, after connecting the extreme ends of secondary to rectifier pcb AC input will we get 12v from joining V+ & V- together (6+6 =12v) and 0v from centre tap?
This scavenged transformer along with the LM3886 amp boards have been tortured enough.
I've decided to build a new amp with a suitable transformer preferably a toroid.
Now, I'll need help with these below.
A) I want to build a stereo amp for 6 ohm, Sensitivity: 86dB/2.83V/m speakers (wharfefdale 9.1)
B) I am aiming at a min of 50 watt / channel
C) Want to add this along with a line level input as well
D) Please advise if this kit is good enough and how much tweaking will be required to set the gain etc to achieve my goals.
E) Will I need a transformer with 22 0 22v x 1 (stereo amp boards) and 0 12 x 1 (BT decoder board)
Please confirm so I can order the amp boards.
BR,
Abhishek
As "Jls001" pointed out Myref rev C will be all together at a different level of chip amp, the amplifier board you mentioned will not be able meet the SQ of Myref.This scavenged transformer along with the LM3886 amp boards have been tortured enough.
I've decided to build a new amp with a suitable transformer preferably a toroid.
Now, I'll need help with these below.
A) I want to build a stereo amp for 6 ohm, Sensitivity: 86dB/2.83V/m speakers (wharfefdale 9.1)
B) I am aiming at a min of 50 watt / channel
C) Want to add this along with a line level input as well
D) Please advise if this kit is good enough and how much tweaking will be required to set the gain etc to achieve my goals.
E) Will I need a transformer with 22 0 22v x 1 (stereo amp boards) and 0 12 x 1 (BT decoder board)
Please confirm so I can order the amp boards.
BR,
Abhishek
ATM I'm struggling at the transformer and rectifier stage. Would love to build either PeeCeeBee or MyRef depending on availability.
It will be around 6.6 Amps, here is a online calculator for converting VA to Amps.Hi All,
For the last 2 days, I've been pondering over a thought of building a LM1875 based GC and based on the info given here
I've done a few calculations with 15 0 15v transformer as a base, please double check them for me.
GOAL: 20W per channel
SPEAKERS: 6ohm
Would like to use a single transformer with a single bridge rectifier
15.49V - PEAK OUTPUT VOLTAGE
+/-22.72V - MAXIMUM SUPPLY VOLTAGE NEEDED BY THE AMPLIFIER
24.66V - MAXIMUM SUPPLY VOLTAGE OUTPUT BY A TRANSFORMER
24.51W - OUTPUT POWER FROM A TRANSFORMERS VOLTAGE RATING
61.65W - REQUIRED TRANSFORMER POWER
92.47W - REQUIRED TRANSFORMER POWER(multiplied it by a factor of 1.5)
184.95VA - Stereo amplifier powered by a single transformer.
From what I've gathered 15 0 15v CT (200VA) transformer should work, how many amps will it roughly be ?
BR,
Abhishek