PTP vs PC board discussion going on here

[VelvetGeorge]

https://www.facebook.com/MetropoulosAmp ... nt_count=1


Some recent backlash against my Metro-Plex using PC boards has prompted a discussion on this. And some clever ideas for a hybrid approach. Feel free to jump in.

george

[JimmyR]

Any backlash would be pure ignorance I suspect. I can't imagine you using PCB George unless you knew it would work as well as tag or turret boards. It's more about layout, ruggedness and component quality than board type. The board you have pictured on FB looks great.

[VelvetGeorge]

It's one part anti pc board bias and another part assumption that anything I do will be PTP. Tough to debunk either way.

These 1/8" thick FR4 boards I made are very robust. I can't imagine a PTP terminal board being better, just different. The PC board has the bonus of being shielded on both sides and produced with tolerances down to .0005" That's incredibly precise! Our boards made in house are around .005" tolerance.

george

[neikeel]

We all know that a good quality well laid out pcb is at least as good as a turret/eyelet board and much neater than pure PTP with components flying everywhere! A difference that a lot of people overlook.

Of course modding and tweaking for those that want to is not good on a pcb. If you are building an amp which has been planned and all the tweaking done for you (i.e. the Metroplex) with high quality components with plenty of fuses and protection then I do not see what the fuss is about.

[JimmyR]

I guess most guys are assuming that all PCBs are the same. If you to use a PCB like Marshall does in it's budget amps, then sure, I'd be concerned! But the early Marshall PCB amps were very well built and have lasted well. It's not the PCB which is necessarily the bad thing, it's poorly made PCBs which cause concern. And as I said, if you are doing it George that should be enough to say that it will be done right.

Not all PCBs are the same.

[Haze13]

Off course we can look at Soldano amps. SLO is a PCB type, and I never heard of complaints... If heaters (ac) are not on the board, and signal path is short, then no one will hear the difference.

[VelvetGeorge]

Here's the mostly finished production amp. 4 pc boards total. More coax than I prefer to use, but the amp is dead silent. As it should be with V1 and V2 DC heated and sensible ground scheme.



george

[chrisom]

VERY NICE-looking piece of engineering..! And perfect timing with Marshall struggling to find their own modern identity...

[herbvis]

That is a CLEAN looking PCBA. I don't expect anything less than high quality coming from metro amps. I think haters will be silenced after they hear the amp.

[rockgod212]

that looks pretty good to me, I wouldn't have guessed it was a pcb amp when I first heard it. nice looking board.

[ezs]

From a practical view, yes PCB. From user friendly view, access is key. If PCB is easily accessible for service or other, that's a win win. Sweet build!

[Elad E]

If PCB is easily accessible for service or other, that's a win win.

I highly doubt these amps will need any servicing other than maybe new filter caps some 20 years from now (like any other amp).

I think PCB has become a synonym for low quality cookie cutter production because that's where it was utilized to the fullest extent in the first place, simultaneously with other cost cutting changes in components, iron and such which amplified (no pun intended) the negative perception of changing over to PCB along with the production changes in other electronic appliances, automotive, furniture and other industries which concurred around the same time.

a well laid out PCB with quality components, quality materials, adequate traces' spacing and width will last and sound on par with the best PTP boards out there but you often won't see this level of attention to detail in run of the mill products as they go the PCB route for the ability to minimize cost in the first place.
I'd bet George's PCBs don't make up for actual saving in money as much as they save time and allow for better consistency from amp to amp which I believe serves the design goals and product positioning of the Metro-Plex compared to the Plexi Replicas line and the various vintage-modern takes on Plexi amps offered by competitors.

I can think of at least one more "hotroded Marshall" style amp maker which is highly esteemed and uses PCBs (which look way more like what you'd expect to find in a late 90s PC than the neat innards of the Metro-Plex).

[FourT6and2]

Lots of high-quality PCB amps out there. A few off the top of my head:

Diezel
Fortin
VHT/Fryette
Bogner
Soldano
Henning

Personally, I prefer a hybrid method of Printed Turret Board. That way components can be replaced more compared to PCB, where that can damage the solder pads. It also means you don't have to lift the board to remove/replace components, as all soldering can be done from the top.

Mako uses this method. On the SLO Clone I built, SOME of the pads on key PCB positions were staked with turrets. Made it a lot easier.