Rauland W-819

Racing

Synchromatic
Aug 30, 2014
521
Sweden
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Now. This is already a sort of story with a twist. For those not in the know Rauland were manufactured in Chicago Illinois USA. Their reputation are..above average. They´re all PA or radios.

So. Ran into that there unit in Holland. Picked it up for a song...when the seller told me he had a few more....

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In contrast to the one in the pics there the other one was claimed to be basically as fresh as can be,seing these amps were made in the -40´s.

Well,"Mr Handyman" sure as hell has a field day with what could best be described as british racing green and a brush. In short..looks like crap. Amps are from the -40´s in turn as Rauland changed their design in a rather vivid way as the -50´s arrived.

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Yep. It sure sports a myriad of tubes. That much is for sure. All octals as can be seen. Please be adviced that some of these Rauland sported all in all 14 tubes!

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Uhu. A 5U4 as rectifier and then a pair of 6L6G´s.

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Seller told me the unit is working,and true enough. A man of his word.

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So. Both amps showed up,and in one piece. Thank yooooooou... The "green monster"...uhu. For lack of better description i´d say that the amp has sure as hell been handled. Mr Handyman and all of that...

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Oh,they are all there alright. Just took the rectifier and powertubes out as i took the pic. Finish of the ENTIRE amp/chassis is "messy"...not that it bothers me all that much TBH though.

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Transformers for the amps sure LOOK a lot different,while the OT´s seems to spec the same. 4/8 Ohms..then for 200 Ohms and 500 Ohms. Some of them taps will,as you could expect,get deleted.

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Within the wings of time. Looks alone sort of verifies the age of the amp.

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Yep. Even sports a fuse,both of the amps. That socket will all them colorful wires is speaker out.

With a twist.
Yeah. With a twist cause see...

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The one aimed for my friend indeed looked a TON better. Beautiful design even.

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Faceplate is lit through two small slots. One for each side. Neat... Lights are regular small bulbs run off of heater voltage.

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Uhu. Duly noted.
Both amps share tube setup 100% btw.

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Nicer nick? Yeah,that and then some! Most likely made in 1948 and clean enough to eat off of!
Notice the placement and proximity for the two transformers.

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Uhu. Completely untouched,complete with old fashion pulldown resistor and what not.

So.
What about that twist? Well. My friend could care less for that beautiful old chassis so..i happily accepted his offer and took the thing under my wings. That means that what´ll happen here is a chassis swap.

That simple.

Now. Guitar amp time.
 

Racing

Synchromatic
Aug 30, 2014
521
Sweden
That 2nd one is Art Deco gorgeous! Don't repaint the faceplate!

Don´t fret. What´ll happen here is that the entire chassis will be wiped clean and picked apart. Then i´ll hit it with some paint cleaner + my trusted old polisher.
Agreed. The entire thing is a work of art.
 

Racing

Synchromatic
Aug 30, 2014
521
Sweden
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Bench always turn into a disaster as i scrap amps. That green monster,chassis is guess would be usable but to what avail really? The one chassis that my friend handed me will come out 100 as i hit it with some paintcleaner and a buffer.
The output transformer in my case has been replaced by a Dutch Amroh. No worries,and as it turns out the specs for it were available online. No harm no foul in other words.

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The powertransformer is absolutely MASSIVE. Guess it won´t budge all that much even at wide open throttle. That said,as you can see the chassis is built up as sort of modules. For the better IMO as that sure as hell makes it easier to build the thing as well as clean the paint out.

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..and that absolutely glorious faceplate. TALK about art deco! Yeah. This´ll turn out real nice with a little work.
 

Racing

Synchromatic
Aug 30, 2014
521
Sweden
Uhu. I asked around a bit before hitting the BIN button and as it turns out Rauland is rather well regarded.

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Drilling into the FP was inevitable. That simple. For modern day n era use coupled with the fact of a firm installed mains wire that brings that i NEED a mains switch that cuts both phase and zero and done deal. Of course this also entails the install of a safety ground.

The hole left in the FP after the stock mains switch...well,what can be more correct than the PPIMV pot taking it´s place?

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So. Hit the chassis with my buffer and sure enough...it downright sparkles now... Install of the two transformers were rather straightforward. Nothing to write home about really. The aftermarket ooutput transformer by Dutch "Amroh" had be a tad worried for a while but...as it turned out all the info ever needed was available online! Talk about homerun huh? Seing the transformer isn´t exactly of todays date...hello.
As it turns out though Amroh has been in business for quite a while,dating back to the -20´s even.'

Still pondering the layout for the circuit tho and..closing up on a decision being needed....
 

Racing

Synchromatic
Aug 30, 2014
521
Sweden
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Yep. Yes,i´m a nerd. So shoot me. Why´s that?
Well...i took to stripping the 70yr old octal sockets down and cleaning them out completely. Retensioning each pin.
Them old ceramic sockets in short got a new lease on life and for lack of better words it just feels right to keep some of the parts the amp was originally made up of.

The transformers came to fit rather well as you can see. Had to open the cutout up a bit for the PT all said and done,but no harm no foul.

Then per usual i´d say. Fuse holders and "saver diodes" vs the tube rectifier and so on. :)
 

russmack

Country Gent
May 1, 2017
1,260
ballina australia
I agree.

I'm pushing seventy.

Interesting stuff, but really over my head. I'd like to take up this sort of stuff as a hobby. Lots of old tube radios around here.

Not enough time left though.

Russ
PS You never know though. Wouldn't take too much to convince me that I should maybe get out and buy a multimeter and basic solder kit.

And if I do - it'll all be your fault, Racing.
 

Racing

Synchromatic
Aug 30, 2014
521
Sweden
PS You never know though. Wouldn't take too much to convince me that I should maybe get out and buy a multimeter and basic solder kit.

And if I do - it'll all be your fault, Racing.
All to happy to be of service :D

However.
All is not well in wonderland.

Fired this thing up yesterday albeit just with the 6L6´s in place and... That 6L6,the 6L6G included,takes a whole lot more plate voltage that stated by datasheet i guess is all clear. However,this time out...a little toooooooo much.
Dialed in as far as anode loss in idle the thing settled at approx 520VDC. Then with zeners in place vs g2 that REALLY makes the voltage takes a dive. None the less..520VDC IS to much to ask.

Mind you. These amps,as many others of the time,use what´s known as a pulldown resistor vs B+. This mainly to keep voltage surge during startup in check,while it of course acts as a pulldown under use too.
In the case of these amps a rather hefty 4,7k unit which amounts to,seing the voltages present,that the resistor sees a tad over 40 watts being burned up in heat. That is a shitload no matter how you regard it,and power that could be put to good use elsewhere.

Amp uses a 5U4 stock,and still does,and a 5U4 hands us a rather heavy voltage drop already as is. Few tube rectifiers will present drops all that much more. Ergo,the pulldown in its own right but it DOES impose on those approx 250mA available out of the 5U4.

So. I opted to install a couple of heavy duty ceramic resistors inline with the AC secondary,which sure works. B+ was now all in at approx 470VDC,adjusted to approx 30mA per 6L6G. All good i guess,however...Q is how it´ll make the amp react as i lean into it.
Only one way to find out i guess.....
 

Racing

Synchromatic
Aug 30, 2014
521
Sweden
Looks indeed like a later repair replacement that Dutch Amroh U70B tranny. I have the U70BN and it's a slighty newer type and looks the same.

To be honest i didn´t even know of Amroh. But there ya go i guess,you always learn something new. Transformer seems of high quality as you check the details.
One thing i did though was to drill out the stock rivets that keep the package together and replaced those with regular screws,thereby being able to adjust torq.
IMO always a better idea.
 
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Racing

Synchromatic
Aug 30, 2014
521
Sweden
Dude, do you ever sleep?

It happens!! :D

Anyways.

Time for a more substantial update then.

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Yep. As it turned out all them sockets were put to good use. In fact,one was added. Lot of tubes? Yeah,but for a good reason.

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Socket description is about on par,apart from the one where a 6SN7 has replaced that 6SC7.

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We´ve touched upon the importance of vibrations vs small signal pentodes. Well. This is about as awkward as that has to be. A pair of regular grommets and done deal.

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Sure enough. One socket has been added,a noval. This to hold an ECC-83/12AX7

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Here we go! A picture is starting to evolve at least. Where the former input jacks used to be we now find the jacks and pots for the loop.

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To preserve board space i´ve set anything "cathode" as a point to point bundle and simply run a wire from there to where it needs to go. It is very rare,IME,that you need to replace or service cathode components so..

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Uhu. ECC-83.

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Might be that that there needs a bit of an explanation.
Yes. There´s all in all 4 coupling caps and these are aimed for use with the PPIMV control.

Try n keep up.
This is in essence a two channel amp. Both channels aimed at rocknroll use. Ie;clean work is of lesser importance. Entry stage for both channels is one of them two 6SJ7´s. After that the signal is headed one of two directions.
Either vs yet another 6SJ7 or vs the twin triodes of that ECC-83 i mention above. The latter i´ve tried many time with VERY good results while the idea of pusing a small signal pentode WITH a small signal pentode is new to me... Previous experiences from this is very limited to me,and the little there is...well,let´s say that the jury has come up hung.
Routing of signal is controlled by H11 optocouplers.

From either preamp the signal then heads for the tonecontrol,which is of the type you´ve seen me fiddle around with lately. Ie; a rather intricate version of the James network. This works SO well that it puts regular stacks and what not to shame so there really is NO excuse not to use it.
Outbound of that James in turn the signal heads for a gainpot,and this gainpot is to control amplitude for the cathode follower triode of a 6SN7,which is the buffer/driver stage for the loop.

Inbound of said loop the signal then hits the other triode of said 6SN7,which is setup as a regular gainstage and heads for yet another gainpot that controls amplitude before signal hits the phaseinverter.
The phaseinverter in turn is a 6SC7,which again is a new acquaintance. Remains to pass judgement on that.

Outbound of the PI the signal then hits the twin triodes of yet another 6SN7,and these are setup as cathode followers...and see this is where the pic above enters as that is one pair of them 4 coupling caps. Signal then heads for the PPIMV pot before being returned and sent on its way vs the powertubes.

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In playing around with the drop resistors of the rail and which wire to head where i kind of F-d up a bit and need to clean them bundles of wires up a bit. Comes with the territory i guess.

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I guess you can all appreciate the logic behind the loop and how it´s placed.
 


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