[ephrank]

Been running my P20 with stock tubes for several months. I've got a 12V linear PSU and some 6N3P-E tubes coming.

Will the upgrades make HE4XX (balanced) sound fuller?

 

[magicscreen]

Been running my P20 with stock tubes for several months. I've got a 12V linear PSU and some 6N3P-E tubes coming.

Will the upgrades make HE4XX (balanced) sound fuller?

I have only an HD6XX and using a SMPS filter unit which give a linear PSU quality. That is huge sound quality difference in a better way. Bigger soundstage, better bass and timbre.
Using the 6N3P-EV tubes, I think they are better than the chinese stock tubes.

 

[ephrank]

Today I listend to my GR07 Classic's on the P20, via Massdrop 2.5mm to XLR adapter. Woah, the synergy was very, very good!

GR07 benefit from that little bit of warmth, the combo is musical, female vocals sounded very nice.

That is huge sound quality difference in a better way. Bigger soundstage, better bass and timbre.

Can't wait for my PSU to arrive

 

[Mark James Richardson]

I bought one of the P20 Amps during the recent Amazon Prime Day Sale.
First thing I did was to open it up, unsolder the 4x JRC-5532 op-amps, and install machined pin sockets.
Then I plugged the op-amps into the sockets, and enjoyed listening to the amp.
I haven't assembled the balanced interconnects that I need for my system, so my Topping D70 is connected to the P20 with RCA cables, and my headphones / earphones are connected to the 6.5mm output jack.
.
Next, I'm going to order some longer 5-Pin FFC Ribbon Flex Cables, to connect the Front Panel Display & Control to the circuit board.
https://www.aliexpress.com/item/32846379613.html

That way, they're less likely to be damaged during op-amp rolling.

Hi David! I am waiting for a P20 to get here which I bought last night and would love to install the machined pin sockets. Would you mind telling me where they can be obtained? This sounds like the most amazing hobby, especially as critical listening is my job as a piano/ music teacher. I am also waiting on some HD6XX cans to arrive. This is my first post and I'm stoked to be here so hello to every one!
ps. In support I have an account at both tube store.com and hifi collective... Loving it.

 

[DBaldock9]

I bought one of the P20 Amps during the recent Amazon Prime Day Sale.
First thing I did was to open it up, unsolder the 4x JRC-5532 op-amps, and install machined pin sockets.
Then I plugged the op-amps into the sockets, and enjoyed listening to the amp.
I haven't assembled the balanced interconnects that I need for my system, so my Topping D70 is connected to the P20 with RCA cables, and my headphones / earphones are connected to the 6.5mm output jack.
.
Next, I'm going to order some longer 5-Pin FFC Ribbon Flex Cables, to connect the Front Panel Display & Control to the circuit board.
https://www.aliexpress.com/item/32846379613.html DON'T Order this cable for the P20.
.
That way, they're less likely to be damaged during op-amp rolling.

NOTE: It turns out that the first set of 5-Pin FFC Ribbon Flex Cables that I ordered - were the wrong width. The correct width longer cable, is this one - https://www.aliexpress.com/item/4000267244213.html

Hi David! I am waiting for a P20 to get here which I bought last night and would love to install the machined pin sockets. Would you mind telling me where they can be obtained? This sounds like the most amazing hobby, especially as critical listening is my job as a piano/ music teacher. I am also waiting on some HD6XX cans to arrive. This is my first post and I'm stoked to be here so hello to every one!
ps. In support I have an account at both tube store.com and hifi collective... Loving it.

The low profile DIP-8 sockets that I bought from Mouser, are the Mill-Max (P/N: 115-43-308-41-003000) - https://www.mouser.com/ProductDetail/Mill-Max/115-43-308-41-003000?qs=sGAEpiMZZMs/Sh/kjph1tvt1/mEPT/XoHngJTF1udAc=
NOTE: These can't be stacked, without damaging the sockets - since the outer diameter of the solder tail is larger than the acceptable range of pin widths that can be inserted.

Because of the height of the P20 case, you don't really need the low profile sockets, so you could order the standard Mill-Max DIP-8 socket (P/N: 110-13-308-41-001000) - https://www.mouser.com/ProductDetail/Mill-Max/110-13-308-41-001000?qs=/ha2pyFadugNqN7TEfSg9dgVPVw4Cip4QS1IvzyqsD4nViX%2B7uIdxq0MjFrVtLjW
These can be stacked, since the solder tails are 0.020 outer diameter, and they can accept pins that are 0.015 - 0.025 diameter.

 

[Mark James Richardson]

Thanks a lot David and I'm thinking for this job I should go to a tech. However by the time it gets here I might be more brave and decide to have a go, never used a solder sucker before... I will definitely make a balanced hp cable though and a mic lead made from silver wire from Hifi Collective, all info sourced from this forum!! Amazing resource.

 

[NiTROAUDiO]

So I am about to purchase some new tubes and a new ps for the p20. Cam this unit handle more than 5 amps ? Like 10amp or 20amp. Or should I stick with 5. Also I'm pretty good at soldering how hard is it adding dip to do op amp rolling

 

[DBaldock9]

So I am about to purchase some new tubes and a new ps for the p20. Cam this unit handle more than 5 amps ? Like 10amp or 20amp. Or should I stick with 5. Also I'm pretty good at soldering how hard is it adding dip to do op amp rolling

The Amplifier circuit is only going to draw as much current as it needs - so a quality replacement 12Vdc power supply that has at least as much output current capability as the stock supply, should work just fine.
According to reviews on Amazon (I'm not at home right now, to look at the supply), the stock supply is 12Vdc @ 1.67A.
Using a much higher current supply (10A - 20A) shouldn't hurt anything, but they will be larger, and probably produce more heat.
The most economical 12Vdc Linear (not switching) 6A - 12A supplies that I've seen, are the Pyramid bench supplies - https://smile.amazon.com/s?k=pyramid+power+supply

If you've got a good de-soldering device (and plenty of desoldering braid - for cleanup), then removing the soldered on DIP-8 op-amps, and installing sockets isn't very difficult.
I've got a Velleman VTDESOL3U, and it works well - https://smile.amazon.com/gp/product/B00B88FRME/

If you look back one page, you'll see where I cut my P20 case in-half, so that the top can be lifted off, to make op-amp rolling much easier.

 

[CADCAM]

Those numbers do sound correct for the stock ps, I replaced mine with a 12V 5amp supply and it made a noticeable positive improvement in perceived sound quality. Not exactly sure why the sq improved but I'd never consider going back to the stock ps. Maybe someone could comment on the benefits of an upgraded power supply, I would assume perhaps a cleaner power and more available in a shorter time frame when the music called for it...

 

[DBaldock9]

Those numbers do sound correct for the stock ps, I replaced mine with a 12V 5amp supply and it made a noticeable positive improvement in perceived sound quality. Not exactly sure why the sq improved but I'd never consider going back to the stock ps. Maybe someone could comment on the benefits of an upgraded power supply, I would assume perhaps a cleaner power and more available in a shorter time frame when the music called for it...

Do you remember whether the power connector is 5.5mm x 2.1mm or 2.5mm?

 

[NiTROAUDiO]

Hey man what op amps and tubes do you recommend for this. Also I am buying XLR cables to balanced 2.5mm to my Fiio Q5 will that give me balanced output. Also can I run 6922 tubes in this.

 

[CADCAM]

Do you remember whether the power connector is 5.5mm x 2.1mm or 2.5mm?

I do not but I will check asap

 

[Mark James Richardson]

I thought it was 2.5... hope so, just ordered a meanwell ps, 12v 6.67 A. My p20 got here yesterday and she sure needs to burn in for an hr or so but then she starts to opens up nicely

 

[Arum16]

Power connector is 5.5mm x 2.5mm. I upgraded to a 12V/6A power supply and had to add a female 5.5x2.1mm to 5.5x2.5mm male adapter.
The original power supply is powering a memory cooler fan. The tubes never get too warm. I'm hoping to extend the tubes' lifespan

 

[DBaldock9]

I do not but I will check asap

I thought it was 2.5... hope so, just ordered a meanwell ps, 12v 6.67 A. My p20 got here yesterday and she sure needs to burn in for an hr or so but then she starts to opens up nicely

Power connector is 5.5mm x 2.5mm. I upgraded to a 12V/6A power supply and had to add a female 5.5x2.1mm to 5.5x2.5mm male adaptor.
The original power supply is powering a memory cooler fan. The tubes never get too warm. I'm hoping to extend the tubes' life span

Thanks for the replies!

Home now - just looked at the connector through a magnifying lens, with a millimeter scale held up to it, and I can confirm what @Arum16 said about it being 2.5mm.