.....allright guys you convinced me, its probably the voltage drop / current - combo; i'll go for +/- 18V then.
I seem to have the new version of the Bursons, components on the outside.
By the way, is 26mV offset low enough to remove the dc-blocking - caps? What about output resistors?
Regards,
Mickie
I seem to have the new version of the Bursons, components on the outside.
By the way, is 26mV offset low enough to remove the dc-blocking - caps? What about output resistors?
Regards,
Mickie
There should be zero offset, there is a blue adjustment pot on the pcb. Mark where it is and adjust.
Brent
Brent
hmm, a bit complicated now to adjust both pots on the modules, i have to desolder them again.....but thanks anyway for your help!
rowemeister said:
Re the LME49720 - I get the warmth back when I put in ANY other op-amp (perhaps not LM6172). I can only assume they're just not burnt in yet. Not given up on them just yet!
SimontY said:Obviously pulling more current AND dropping lots of volts is a HOT combination. A bit more extreme but in my CD player I have an LM317 that drops ~20V to 11V and supplies over 400mA. It makes the quite large heatsink too hot to touch for even a second...
(I won't be leaving it like that forever)
Hi Simon
Are you doing "IT" again ?
Glenn2 said:
IMO LME49720 needs some time to burn in... after 1 week my preamp started to sing.....
Ricardo
I mentioned a while ago about a opamp based phono stage we were building for someone and HERE it is. The prototype was comparable with the Trichord Dino so the final running version should be a little better.
My version for the work pre amp will have better resistors and caps on board 😀
Brent
My version for the work pre amp will have better resistors and caps on board 😀
Brent
Hi Brent, Have you bipassed the 4.7uF Ampohm with the Mundorf (PP) or is it for a seperate job?
Very nice board, esp for a prototype.
Very nice board, esp for a prototype.
This pcb is the final pcb.
The Mundorf MKP are on the input and the Ampohm are for output. The Ampohm are better than the MKP sonically. My own version will use Mundorf Supreme for i/p and o/p from Lee.
Brent
The Mundorf MKP are on the input and the Ampohm are for output. The Ampohm are better than the MKP sonically. My own version will use Mundorf Supreme for i/p and o/p from Lee.
Brent
Hi Brentrowemeister said:
Another awesome piece of work.
The Riaa filter is active or passive ?
Can you provide a schematic ? (Or is it top secret ?)
What are the cap values for the Riaa eq stage ?
Ricardo
Hi Ricardo
There is the usual 100pF on the input to gnd and a cap network on the feedback filter that consists of 2x 4n7 1x 10n and a 18K res. This is MM only but I am developing a switching cct for the guy so MC step up transformers can be used.
The circuit diagram is still secret squirrel at the moment. Don't worry your stage is better 😉 .
In the work pre amp the audio from the phono stage will be going through a fet buffer.
Brent
There is the usual 100pF on the input to gnd and a cap network on the feedback filter that consists of 2x 4n7 1x 10n and a 18K res. This is MM only but I am developing a switching cct for the guy so MC step up transformers can be used.
The circuit diagram is still secret squirrel at the moment. Don't worry your stage is better 😉 .
In the work pre amp the audio from the phono stage will be going through a fet buffer.
Brent
Thank you Brent.
Why the need for a TX in the MC case ? Is it coupling to 47k input load ?
Ricardo
Why the need for a TX in the MC case ? Is it coupling to 47k input load ?
Ricardo
Hi,
...so here is an update on the Bursons. I increased the voltage to about 20V; voltage drop on the regs is exactly 5V because the Bursons draw more power - so the voltage drops a bit before the regs.
Still the regs AND the modules are putting a crazy amount of heat to the system (heat on the regs is a bit less but the Bursons getting hot now; so the heat is just...divided to both).
Well, I'm afraid to shorten the lifespan of my Black Gates and other regs because of the heat....
Obviously these Bursons just don't work in my system - so i'm going to dump them.....too bad.
Oh and yes, i checked everything for shorts or bad solder joints etc.
Regards,
Mickie
...so here is an update on the Bursons. I increased the voltage to about 20V; voltage drop on the regs is exactly 5V because the Bursons draw more power - so the voltage drops a bit before the regs.
Still the regs AND the modules are putting a crazy amount of heat to the system (heat on the regs is a bit less but the Bursons getting hot now; so the heat is just...divided to both).
Well, I'm afraid to shorten the lifespan of my Black Gates and other regs because of the heat....
Obviously these Bursons just don't work in my system - so i'm going to dump them.....too bad.
Oh and yes, i checked everything for shorts or bad solder joints etc.
Regards,
Mickie
All the Bursons i've used run mildly warm! You really must have an issue elsewhere.
Do they get hot with no interconnect connected to the cdp?
Brent
Do they get hot with no interconnect connected to the cdp?
Brent
Hey Brent,
....my head also runs hot because of hard thinking what my issues could be..
-regulator issue
-faulty Bursons
-PSU too strong (?)
-bad solder-joints on the op-amps themselves (i could solder new leads)
The point is i did a lot o this and other players, but never had such issues.
BTW, i'm beginning to get accustomed a bit to the new sound.
While i'm typing this i unplugged the interconnects; maybe the burson got a tiny bit cooler (heatsinks on the regs still hot, touchable for about 2 seconds) but this could be pure imagination......ehm...no...checked again, nothing substantially changed.
yours desperately,
Mickie
....my head also runs hot because of hard thinking what my issues could be..
-regulator issue
-faulty Bursons
-PSU too strong (?)
-bad solder-joints on the op-amps themselves (i could solder new leads)
The point is i did a lot o this and other players, but never had such issues.
BTW, i'm beginning to get accustomed a bit to the new sound.
While i'm typing this i unplugged the interconnects; maybe the burson got a tiny bit cooler (heatsinks on the regs still hot, touchable for about 2 seconds) but this could be pure imagination......ehm...no...checked again, nothing substantially changed.
yours desperately,
Mickie
Change opamp to OPA-SUN , upgrade to Audio-GD clock , RCA Jack upgrade to Switchcraft than wire with 6N Silver Wire, the chasis putting bitumen now the chasis more solid and heavy the weight like CD63se
and the section i upgrade below
PSU Regualtor - Black Gate STD
OPAMP - Black Gate N
HDAM - Panasonic FM
Analog Output - Black Gate STD
The blackgate really do wonders.
and the section i upgrade below
PSU Regualtor - Black Gate STD
OPAMP - Black Gate N
HDAM - Panasonic FM
Analog Output - Black Gate STD
The blackgate really do wonders.
Nice work.
Are you going to add separate regs for Dac analog & digital etc. Even using 7805's will bring good improvements.
Cheers, Lee.
Are you going to add separate regs for Dac analog & digital etc. Even using 7805's will bring good improvements.
Cheers, Lee.
mickie said:
The fact the Bursons are getting hot does suggest they are causing the regs to cook. I would desolder them and fit sockets to the marantz pcb and also fit some sockets on the Burson by soldering the legs to the socket. This way you can unplug them in and out and also test other opamps.
Brent
ccschua said:Change opamp to OPA-SUN , upgrade to Audio-GD clock , RCA Jack upgrade to Switchcraft than wire with 6N Silver Wire, the chasis putting bitumen now the chasis more solid and heavy the weight like CD63se
and the section i upgrade below
PSU Regualtor - Black Gate STD
OPAMP - Black Gate N
HDAM - Panasonic FM
Analog Output - Black Gate STD
The blackgate really do wonders.
Sweet.
Change the 2 35V 470uF Silmics for Pana FC 25V 4700uF of Black Gate if you can afford them.
Brent