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Posted: Wed Nov 08, 2006 4:07 pm
by bclaire
rrrajo posted this and I thought it was worth a sticky in technical:

Here is a layman's explanation of the different types of Amplifier construction:

Point-to-point - Each component is connected to a tube pin or solder lug or jack. There are no "boards" whatsoever. Examples of this style of construction include most old tube hi-fi equipment, 70-era Sunns, and more recently BadCats.

Tag Board - the classic Fender and "plexi" construction methods. Most components are soldered to a long board with eyelets. These are in turn connected by wire to the tubes, transformers, pots, etc.

Turret Board - The classic Hiwatt/Harry Joyce style, this is similar to tag board construction, but uses metal turrets which extend out from the board, which most of the components are connected to.

Partial PCB - Used by most modern large manufacturers starting in the late 70s/early 80s. Most components are soldered to a Printed Circuit Board, which has copper lines or traces on the underside of the board surface that the components are soldered to, and which also make circuit connections. Example of this style of construction include the early (vertical input) JCM800s, Biacrown-era Hiwatts, and Soldano SLOs. This method basically used the PCB as an advanced tag board, and many wires are still needed to connect the tubes, etc.

Total PCB - Used by most modern large manufacturers starting in the mid-80s to the present day. Everything is soldered to a PCB, including pots and tube sockets. This makes it easier and cheaper to manufacture, but harder to service and modify, and there is some question about the reliability of the PCBs holding the sockets of the extremely hot power tubes.

This always comes up now and then, and I thought it was good info.

Posted: Thu Nov 09, 2006 1:00 pm
by Simon Wicks
Hi, just a few comments i'd like to make.

Tag boards or tag strip is generally though of as paxolin boards with tags like this pic here {from the Ampmaker site}

Image

Old voxes were made from this and more recently the Cornell series of amps. Marshalls never used this method of construction. Marshalls from the first JTM 45 up to those from around '73 utilised Turret Board construction, then Partial PCB, then in the mid to late eigties total PCB.

There is also another type of construction method: PCB turret board. This is a combination of PCB tracks with turrets. This allows easy replacement of components while retaining the excellent mechanical stability of PCBs. This was invented and is exclusively used by Matamp, who came up with the idea after having to fix many Hiwatts noting the only problems were the wires linking the turrets breaking off.

Posted: Thu Nov 16, 2006 8:18 pm
by Misha
I can tell, that ptp a kind of structure though - the majority of labour consumption, but it also, brings appreciable results in sounding by a guitar and the amplifier as a whole. In general it is a pity to me, that p-t-p leaves for histories, and in a place with it and sounding of 20-th century.

Posted: Sun Jun 01, 2008 1:36 pm
by hamfist
Just FYI, Vox are now using the PCB turret board construction method in their Heritage series amps. So it's not only Matamp that are using that method now. (Simon was obviously correct in his initial post - in 2006 - as the Heritage amps were not around then). I've not heard of anyone else apart from Vox jumping onto this type of construction though.

Posted: Sat Nov 08, 2008 3:55 pm
by Simon Wicks
also Fender used to make their boards on cards punched out with eyelets.....they didnt really use tag boards.

Re: Different types of amp design & construction

Posted: Sun Dec 13, 2009 10:40 pm
by esch
Would the hand-wired (or hard-wired) Tiny Terror fit into the category of Point-to-Point?

Re: Different types of amp design & construction

Posted: Mon Dec 14, 2009 9:05 am
by Nork
yup. there's a pic floating around Image

Re: Different types of amp design & construction

Posted: Mon Mar 15, 2010 10:56 pm
by GunniWaage
Hi new to the forum here :)

In wich category would the AD30HTC fit in ?

Cheers from Iceland :D

Re: Different types of amp design & construction

Posted: Mon Apr 05, 2010 9:40 am
by mikelangelo11
As far as I know it fits into point to point category.Do you have Orange AD30HTC? I played one at my local shop , it sounded great.

Re: Different types of amp design & construction

Posted: Tue Apr 06, 2010 5:01 pm
by nguideau
The AD30 is based on a PCB.

Re: Different types of amp design & construction

Posted: Fri Aug 13, 2010 6:18 pm
by a.hun
PCB. The green bit with lots of white printing and copper lines is your printed circuit board.

In fact apart from the rare modern Custom Shop amps Oranges have ALWAYS been PCB construction. Though they used to chassis mount the valves instead of mounting them on the PCB itself as is done these days. However if the board itself is strong enough (yes) and is properly reinforced with spacers (yes) than unless there are any heat related problems (not so far) there shouldn't be any real big reliability issues. :D

Properly done PCB is just as reliable as any other build method, and is actually less likely to have noise issues due to random positioning of wiring, components etc. With PCB build everything is all laid out pretty much exactly the same from amp to amp. It is really just cheaply put together PCB electronics that give the technology a bad name. But a poorly built amp is poorly built even if that is all done PTP by hand! :wink:

PTP is in no way inherently more reliable than PCB. See this thread HERE comparing old Marshalls and Hiwatts, in particular posts #15 and #22.
During the later 70s Marshall went to PCB construction, but the reliability didn't drop at all at with that change. It was only years later (around 1990) when that happened, when they introduced a new range (JCM900) which were built to a price instead of to their own traditional high standards. The 70s Marshall amps (both pre PCB and PCB built) being discussed on that thread, alongside '70s Hiwatts, vintage Oranges and just a few others were (and if well maintained still are!) about as reliable as any amps ever built.

Remember though, there is more in many modern amps to go wrong than with those simpler older amps. Have a look at the inside of my OR120. Ignoring the (non original) doubled up capacitors on the PCB there is a lot less happening inside there than in your RV, right?
Image

Your amp (like my Rocker 30) is put together to a pretty decent standard. Not the worlds best quality, but no huge issues either IMO. (Use of press on spade connectors being by far my biggest complaint!) Well above average run of the mill build quality at any rate.
But... with more complicated circuitry like the more complex modern amps there will inevitably be more potential for things to go wrong. Thats just the way it is and the reason why a lot of us believe simplest is usually best. Even so the vast majority of all problems with good quality modern valve amps are with the valves themselves. Keep a couple of spare valves and fuses handy and you and your amp will be fine!

Happy? :)


Andy.

Re: Different types of amp design & construction

Posted: Thu Nov 03, 2011 7:40 pm
by Vince Neville
Hi everyone,

This is my first post here in Orange world. I am building an amp whose preamp is partially inspired by the OTR120, and I'm looking forward to learning more about Orange amps.

The URL below is where the information in this thread comes from - word for word. Now, we all know who to thank - Mark Huss.

http://mhuss.com/AmpInfo/" onclick="window.open(this.href);return false;

All the best.

Re: Different types of amp design & construction

Posted: Thu Oct 23, 2014 5:26 am
by blackbee045
Tiny Terror fit into the category of Point-to-Point?

Re: Different types of amp design & construction

Posted: Thu Oct 23, 2014 7:53 am
by Bensnake
blackbee045 wrote:Tiny Terror fit into the category of Point-to-Point?
Nope. There's, however, a hard wired version made in the UK.

Re: Different types of amp design & construction

Posted: Thu Oct 23, 2014 10:32 am
by bclaire
blackbee045 wrote:Tiny Terror fit into the category of Point-to-Point?
If you buy a hand-wired one, yes.
If you buy the typically available one, no.