Was posted somewhere. Apparently there is more than one version, though.
The top must slide off, since there seem to be slots in the top frame of the chassis.
Yep, the fact is that I would have chosen a pic without carpet in the background... ☕
Not mine. Just a photo someone else took. Do you have a better one? If not, quit the criticism.
I would not own one of these.
Sorry, no criticism at all.
I meant: is there a reason why you can't take a pic of your own appliance?
May be I lost something...
Thanks to all for your thoughts.
The solution probably is a slide out after taking off the front knob, as @anabel suggests. I took off the front knob, and some remaining back screws and couldn't slide it. I then started taking out screws from the bottom, but changed my mind. Too many screws. I didn't want to accidentally loosen something important on the board. It is a fine sounding preamp. I don't want to break it.
If op amp rolling was as easy and harmless as tube rolling I would give it a try. In this case it is not.
By the way I tried the suction cup approach and the top didn't budge.
It seems the manufacturer and distributor/retailer encourage op amp rolling based on the Shenzhenaudio website and my correspondence with Gustard. (Gustard did not respond to my request for instructions on top removal)
From the Shenzhenaudio website :
Op amp + discrete hybrid architecture, which ensures circuit consistency and no lack of adjustability. Two in-line LM49860 dual op amps can be replaced to increase playability.
https://shenzhenaudio.com/products/gustard-p26-fully-balanced-preamp-lm49860-hifi-pre-amplifier
The solution probably is a slide out after taking off the front knob, as @anabel suggests. I took off the front knob, and some remaining back screws and couldn't slide it. I then started taking out screws from the bottom, but changed my mind. Too many screws. I didn't want to accidentally loosen something important on the board. It is a fine sounding preamp. I don't want to break it.
If op amp rolling was as easy and harmless as tube rolling I would give it a try. In this case it is not.
By the way I tried the suction cup approach and the top didn't budge.
It seems the manufacturer and distributor/retailer encourage op amp rolling based on the Shenzhenaudio website and my correspondence with Gustard. (Gustard did not respond to my request for instructions on top removal)
From the Shenzhenaudio website :
Op amp + discrete hybrid architecture, which ensures circuit consistency and no lack of adjustability. Two in-line LM49860 dual op amps can be replaced to increase playability.
https://shenzhenaudio.com/products/gustard-p26-fully-balanced-preamp-lm49860-hifi-pre-amplifier
They are pulling your leg, what is newer and better than LM49860?
Just see about that first.
Then build your own.
And remember, a slew rate greater than 15v/ micro second is of no use in audio.
That is TL072 territory. You have a much more recent chip inside. And it is obsolete now.
Like driving a sports car in rush hour, not much use rolling op amps. It will still take the same time as a simple car to pass the same distance.
https://www.head-fi.org/threads/lm4562-lme49720-lme49860-do-they-sound-different-to-you.521972/
Enjoy...
Just see about that first.
Then build your own.
And remember, a slew rate greater than 15v/ micro second is of no use in audio.
That is TL072 territory. You have a much more recent chip inside. And it is obsolete now.
Like driving a sports car in rush hour, not much use rolling op amps. It will still take the same time as a simple car to pass the same distance.
https://www.head-fi.org/threads/lm4562-lme49720-lme49860-do-they-sound-different-to-you.521972/
Enjoy...
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Yes, I was lost that the OP is not you! 😳
Sorry if I took an oversight, but Google Translate also translates the names of the forum members with absurd names and then I swapped your "identities" since you immediately posted a pic after JMFahey request and then I automatically thought you were the OP...
No criticism at all.
There is much praise on the net for Burson and Sparkos op amps. What you say my be true, but I like to decide for myself with my own ears.
No. Mine is black and doesn't show the seams clearly when I photographed it. The ones off the net were clearer than what I could get.
So exactly how does the top cover come off?
Why does the knob have to come off first, is there a screw hidden under it that retains the top cover?
Why does the knob have to come off first, is there a screw hidden under it that retains the top cover?
I don't know for sure because I gave up. However, anabel's suggestion seemed to make sense since nothing loosened the top, implying more screws needed to come out.. Anabel said :
The pictures do not show any screw in he top.
I suggest you remove the front knob, then the 6 screws in the back around the perimeter and finally try to pull gently the back to see if it slides out of the cabinet.
That is the way many devices are assembled.
I hope it helps.
I would compare slew rates and decide, not much is improved above 15 in audio, and above 30 there are chances of oscillation.
Building a new one is a better option.
Building a new one is a better option.
LM49860 has s slew rate of 20V / us, quite good enough, I feel there is no need for op amp rolling.
https://www.diyaudio.com/community/threads/burson-v6-discrete-opamps.370774/
https://sparkoslabs.com/discrete-op-amps/
Audiofoolery, IMO.
It is your time and money, your choice.
There are opinions on the net saying NJR parts sound better than ST and TI parts with the same part numbers.
I am offering no comment further than that.
https://www.diyaudio.com/community/threads/burson-v6-discrete-opamps.370774/
https://sparkoslabs.com/discrete-op-amps/
Audiofoolery, IMO.
It is your time and money, your choice.
There are opinions on the net saying NJR parts sound better than ST and TI parts with the same part numbers.
I am offering no comment further than that.
Okay.
May be a more successful way in order to safe remove the top is asking in the following thread
https://www.audiosciencereview.com/...asurements-of-gustard-p26-preamplifier.10492/
I think the OP or someone else will gladly provide you with the information you need.
I built a phono pre amp using TL072 for less than $10.
The chip was like 20 cents, and I had put a socket to compare.
I would advise doing that instead of opening the unit.
Bear in mind that a variable power supply, and variable input and output pots will help you tune the system better for different op amps.
They do not have the same optimum voltage or the same impedance in and out values...which the op amp rolling people do not tell you.
The chip was like 20 cents, and I had put a socket to compare.
I would advise doing that instead of opening the unit.
Bear in mind that a variable power supply, and variable input and output pots will help you tune the system better for different op amps.
They do not have the same optimum voltage or the same impedance in and out values...which the op amp rolling people do not tell you.
