ccschua said:
Hi ccschua
Would you please explain your comments ?
Why do you state it is not recommended to change opamps ?
Inittialy I tryed LM4562 (Wonderfull full sound, loads of detail and powerfull bass) and these are so good you can wire them directly to the output, bypassing the output resistors and caps.
The new metal can opamps are even better (I am using one in my modded Meridian101b with outstanding results).
Do you mean you replaced the opamps by some discrete devices and are still using hdam ? (I guess there is something wrong elsewere in your player)
Ricardo
RCruz said:Hi Brent
Do you believe Burson opamp solution to be as good as the DOS ?
Maybe because it does not need an output cap ...
IMO removing HDAM is a must if you want to use a good opamp.
But you should also consider powering the several chips with dedicated psu.
Ricardo
If the standard opamps are 0% , LM4562 are 60% , HA version 70% , Bursons are 95% and the Dos 100%.
That's how close it is. Both need good regs etc to sound their best.
Not having to use an output cap is also a large bonus.
Brent
Hi guys,
I'm not posting this just to be contrary, but I did mention a while back I was experimenting with the LME49720HA op-amps so I may as well post my conclusions.
I didn't much like the LM4562 and I don't like the tin-hat version either. This is just down to taste of course. I'm not saying they are bad, just that I don't like them. I've tried them in other devices too. I settled on 2xAD825 in the end (though the AD8065+AD8610 combo was close). The ADs and LMs sound better without HDAM in circuit, unlike some BB op-amps which seem to struggle.
Interestingly (or not!) I did a shoot-out in my tuner last year. I used the Brown Dog SIL-8 adaptors and tried 2xLME49710, 2xAD8610, 2xOPA627 and 2xAD825. The AD825 won this battle too.
I guess I just like what this op-amp does and dislike what the LMs do. To me they sound clean but boring, with thin vocals. There's nothing that screams at you to turn it off, you just don't get absorbed in the music.
Anyway, just my opinion (though it seems quite a common one on other threads, just not this one).
I've also noticed that these days Audiocon like to used the LM in filters but say the AD825 is much better for ouput duties.
Also, have Burson stopped calling their discrete op-amps HDAMs now? I always thought that was rather funny!
Glenn
I'm not posting this just to be contrary, but I did mention a while back I was experimenting with the LME49720HA op-amps so I may as well post my conclusions.
I didn't much like the LM4562 and I don't like the tin-hat version either. This is just down to taste of course. I'm not saying they are bad, just that I don't like them. I've tried them in other devices too. I settled on 2xAD825 in the end (though the AD8065+AD8610 combo was close). The ADs and LMs sound better without HDAM in circuit, unlike some BB op-amps which seem to struggle.
Interestingly (or not!) I did a shoot-out in my tuner last year. I used the Brown Dog SIL-8 adaptors and tried 2xLME49710, 2xAD8610, 2xOPA627 and 2xAD825. The AD825 won this battle too.
I guess I just like what this op-amp does and dislike what the LMs do. To me they sound clean but boring, with thin vocals. There's nothing that screams at you to turn it off, you just don't get absorbed in the music.
Anyway, just my opinion (though it seems quite a common one on other threads, just not this one).
I've also noticed that these days Audiocon like to used the LM in filters but say the AD825 is much better for ouput duties.
Also, have Burson stopped calling their discrete op-amps HDAMs now? I always thought that was rather funny!
Glenn
"And that's what the Hyper Dynamic Amplification Module is. Please note that this opamp module is nothing to do with the HDAM technology used in Marantz products. "Glenn2 said:They used to call them HDAM.
Well, they seem to like the name nevertheless.
Maybe the name has a special effect in the final user... I am imagining what a metal can enclosed bursonv2 with lazer encryption could do.
RCruz said:
Hi ccschua
Would you please explain your comments ?
Why do you state it is not recommended to change opamps ?
Inittialy I tryed LM4562 (Wonderfull full sound, loads of detail and powerfull bass) and these are so good you can wire them directly to the output, bypassing the output resistors and caps.
The new metal can opamps are even better (I am using one in my modded Meridian101b with outstanding results).
Do you mean you replaced the opamps by some discrete devices and are still using hdam ? (I guess there is something wrong elsewere in your player)
Ricardo
I am still using the onboard HDAM in the Marantz cd63. I heard before without the onboard HDAM, it cause a mute problem (on off pop sound).
Now I took the opamp (the two 8 pin opamp) out and replace with OPA SUN V2. OPAMP is no where near the discrete. and some will argue discrete is no where near the tube.
OPA SUN V2 is not the same as Burson HDAM.
If u want to know more about OPA SUN V2.
http://www.audio-gd.com/enweb/pro/diy/OPA.htm
True. Even the audio-gd clock is also replaced with the blackgate lol. I am trying to isolate the power supply to the OPA Sun V2. I hope to use charge transfer circuit to power it up. For more info about charge transfer (which is used in the space industry anyway), visit TDA1541A ultimate.
stueyh said:
Did you match the 10k and 27k resistors between the DAC and first op-amp?
You usually get some offset from the DAC, but there is no reason for it to differ between left and right.
In my 63 and 67, it was about 20mV - 25mV, and coming from the DAC (difference between LO & LON, and difference between RO & RON).
The HDAM can disguise these offsets as they often have 10-20mV of their own.
On my 63 with HDAM it was +35mV/+15mV until I removed the HDAM and it was +25mV on both channels. Not enough to matter anyway.
rowemeister said:
I almost agree! I'd say there was a bigger gap between opamp and discrete!
I've now got a Burson as an I/V stage in my TDA1541 player and a DOS as the output. It sounds awesome!
rowemeister said:
Not using a cap, does that statement also count for decent ones ike supreme??