LM4780 feedback

[littlerick]

I am hoping to build a stereo system using 2 seperate channels. Its my first go so im not entirely sure..

He he I feel like a cat going in a dog cage blindfolded... its gonna be great

[lanchile]

Originally Posted by littlerick

I am hoping to build a stereo system using 2 seperate channels. Its my first go so im not entirely sure..

He he I feel like a cat going in a dog cage blindfolded... its gonna be great

Lol.Do not worry to much buddy! Here you will get all the help you need to build your amp.Here at Diyaudio there are a lot pro in this business.Good luck.

[littlerick]

I have a Sony amp... Just happens to have a torodial transformer in it... heres specs from manual..

Amplifier section
DIN power output

TA-FB730R: 100 W + 100 W (4 ohms at 1 kHz)
60 W + 60 W (8 ohms at 1 kHz)
Total harmonic distortion
Less than 0.008% (at 10 W output)
Frequency response
PHONO (20 Hz - 20 kHz): RIAA equalization curve
±0.5 dB
TUNER, CD, AUX, TAPE1/DAT, TAPE2/MD:
7 Hz - 100 kHz+0
–3dB
S/N (network A)
PHONO

TA-FB730R: 90 dB
TUNER, CD, AUX , TAPE1/DAT, TAPE2/MD:
105 dB
Output voltage/impedance
REC OUT 1, 2: 150 mV, 1 kilohm
PHONES: 10 mW (at 8 ohms)
Speakers impedance
4 - 16 ohms, 8 - 16 ohms (SPEAKERS A+B)

Will my kit be better (presuming it works) than this and will the transformer work with 4780?
It sounds close to what I need.

[lanchile]

Originally Posted by littlerick

I have a Sony amp... Just happens to have a torodial transformer in it... heres specs from manual..

Amplifier section
DIN power output

TA-FB730R: 100 W + 100 W (4 ohms at 1 kHz)
60 W + 60 W (8 ohms at 1 kHz)
Total harmonic distortion
Less than 0.008% (at 10 W output)
Frequency response
PHONO (20 Hz - 20 kHz): RIAA equalization curve
±0.5 dB
TUNER, CD, AUX, TAPE1/DAT, TAPE2/MD:
7 Hz - 100 kHz+0
–3dB
S/N (network A)
PHONO

TA-FB730R: 90 dB
TUNER, CD, AUX , TAPE1/DAT, TAPE2/MD:
105 dB
Output voltage/impedance
REC OUT 1, 2: 150 mV, 1 kilohm
PHONES: 10 mW (at 8 ohms)
Speakers impedance
4 - 16 ohms, 8 - 16 ohms (SPEAKERS A+B)

Will my kit be better (presuming it works) than this and will the transformer work with 4780?
It sounds close to what I need.

Well the easy way to find out if you can use that transformer is by measuring the voltage on the secondaries, if it is in the safe range for your IC. I believe the LM4780 is two LM3886 in one. I am not so sure but 22vac x 2 and 300vac transformer will do.Correct me if I am wrong guys!. I know for sure this spec is excellent for the LM3875 no doubt!!

[AndrewT]

the 60W into 8r0 tells us that the transformer voltage will be about right for a 3886 driving 8ohm speakers.
You will need to measure the actual secondary voltages to check if this is so.
This transformer cannot be used for chipamps driving 4ohm nor 6ohm speakers.

The dual amplifier chipamp cannot dissipate as much heat as a pair of 3886. This makes the 4780 run hotter than 3886s driving a pair of 8ohm speakers.
Running the 4780 on slightly lower supply voltages will help mitigate this heat dissipation problem. This heat problem may work against using your existing transformer with a 4780.

[ted4412wilt]

Unless your Sony has stopped working you are better off using it. Chipamp will not be better than that. Very unlikely that the transformer will be low enough voltage for proper operation of Chipamp. Most discrete amps use higher voltage. I have a larger Sony that I use for my main amp and like fine because it has 4 ohm switch unlike most receivers.

[littlerick]

Thanks for info... I'll be back!

[sangram]

I have a Sony ES222 120 watt stereo power amp (the Es is one of the premier Sony lines) and my P2P chipamp beats it in fidelity. The Sony has more muscle for sure, but it is not even close in terms of resolution and soundstage, no contest.

[lanchile]

Originally Posted by sangram

I have a Sony ES222 120 watt stereo power amp (the Es is one of the premier Sony lines) and my P2P chipamp beats it in fidelity. The Sony has more muscle for sure, but it is not even close in terms of resolution and soundstage, no contest.

You are completely right!. Chip amps can kick some a$$ and I know for sure,since I and some friend have compared some good commercials amps side by side blind folded .We have bring big fellas but we did not compared the power but the sound quality.We got Adcom, Portal Panche, Arcam, Acurus and the famous Bryston B60.again We did not compared the power but the sound quality.We were amazed how good these chipamps can sound as good or better than some of the above amps.if a chipamp is well designed...for sure it will beat many good commercial amps!