Friday, November 30, 2018

Tea for the Solderman







The following is a discussion taken from the German-language forum Musiker-Board, and translated into English by Google. The subject is a Fender Princeton Reverb II guitar amplifier. The discussion begins with the original poster's euphoria and ends with his indignation. 


The photographs of the interiors are the original poster's; the external photographs are of another Princeton Reverb II. The video at the end was made by a happier owner.











haqri1220
# 1


Hi Guys! 
I bought a PR II (Rivera) with much euphoria, cheap, I think. After cleaning rags and vacuum cleaners, the amp looked like the box. Really great clean sound. Well, the distortion is more of a joke. I've had such a box before, but I did not really understand it. The claims change. Current device counts about 34 Lenze, and has, if it comes up 200 stress-free hours, in almost exclusive home operation. What sounds good made me think of the first thought of the capacitors and other components with expiration date. I have informed myself across the web, about some service and conversion options. My technical usefulness ends just behind the soldering of guitar cables. I think, but I would still be able to replace capacitors. Of course, tubes also replace tubes. Adjust bias, rectify rectifier, or give sense to the channel, which seems to be possible, rather not. 
Can someone please help me with knowledge and tips? My 1/4 knowledge is mainly related here: http://www.stratopastor.org.uk/strato/amps/prii/PRII_hub.html 
Thanks and Regards 
Hari

Beer ham
# 2


If you do not know what the proposed changes are and are not experienced in the field of electrical engineering, let alone have the tools to check the amp, then give the amplifier but rather in someone's hands, who knows what he does. You can describe to a capable technician what you do not like sound and he will then be able to tell you what is feasible and what is not possible with the amp. 
This is more meaningful than doing soldering exercises and not being able to help out with the smallest problem.

haqri1220
# 3


I would not do it myself. My concern is to find out from users, with practical reference, what is feasible to transport this to a professional. Not every Teki had ever stuck his piston in a Rivera amp. The discreet construction of the amp favors creative changes, but for dizzying I'm € 120 the hour too high. Also very interesting for me would be estimates of the life of capacitors. Because, if there is no acute reason for renewal, I simply do not do anything.


Beer ham
# 4


If you are satisfied with the amp, just play it and do not change anything. 
Nobody knows your amp, so no one can tell if there is a need for service. 
There you would have to agree to the tech and a review. Usually you get something like 30-60 €, if nothing else is to do and it is free, if proper repair / maintenance work is due. 
But you should check with your technician.


haqri1220
# 5


I want to know something more, because, due to age reasons and dehydration burst capacitors I do not want. This messes up the board. And nobody knows what nobody knows.



Dr Dulle
# 6

Originally Posted by haqri1220
I want to know something more, because, due to age reasons and dehydration burst capacitors I do not want. This messes up the board.



sorry my glass ball does not funzt, must first for repair................ ?? 
therefore stop on beer ham; go to the technician and let the look into the amp throw! 
(everything else is rumored)


Smoke165
# 7


Originally Posted by haqri1220

I want to know something more


It may be that the amp is buzzing when the electrics are old / through. Otherwise, you can only look at the capacitors eig, if there are already traces of discharge or have the Elkos bumps. But nobody can tell you more precisely. I would check the Elkos on sight and if the amp itself runs smoothly and optically not noticeable, the box just play. If something does not work out, it can be because of everything. Forecasts are impossible. If you want to play it safe, there is no way around the tech.And if that is good, he will already know what he has to look at.


haqri1220
 # 8


One can not entrust any weak-current sexual, a higher-quality tube amp. Please do not take this too seriously with the guitar cable. I would do it myself, again, not anyway. 
Thx Smoke, I can draw something out of it! Runs way round, but I want it to stay that way at least


haqri1220
 # 9


Who does not know this amp, can not really do much with my previous information. 
The PRII was Fender's last hand-wired production model. Based on the sound of the early Princeton Reverbs, only 7 Watts more. Designed as a practice and studio amp, but with 22 watts RMS very livetauglich. 
No amp with two channels, one amp with two faces. 
Clean, beautiful, warm tube sound, treads are graciously accepted. Reverb very fine, but screwed on the side wall of the amp, that should be changed and screwed to the bottom plate. Supposedly helps the Reverb. Official Cleansound. Everything great. Can be booster with foot switch. Volume difference is supposed to equalize on the board. It would be necessary. 
By pulling the Volume Poties you activate the, but very strange-sounding, distortion circuit. These too can be dramatically improved. The rectifier (diode) can be improved with a simple measure. But there's a need for the tech product experience. Reverb and Zerrschaltung divide a tube. In Zerre no reverb. 
Most owners play it as a cleanamp without a footswitch. I do too, but if I have to fumble, because capacitors are old, then I would make other, necessary improvements.


haqri1220
 # 10


Here are some photos of the inner workings of the destroyer.

Smoke165
 # 11


The Elkos I'm not sure if the brown stuff is normal or outflow, who has to judge differently. The right of the two photographed preamp tubes, however, is milky, which has almost certainly drawn air and is in the bucket. You should swap, that can also yourself. Old out, new in, finished. Vll sounds because of the Zerre also lousy? It may be, that works only in the channel (do not know the amp itself).


bluesfreak
 # 12


The tube on the right is broken, the air has drawn, please no longer use the amp with this tube! 
The Mallory Elkos are also finished, both have already puked electrolyte, which should all three new. You should also exchange the big Multican ...

haqri1220
 # 13


Thx Smoke! 
The two 6V6GT are the tailpipes. Setting the bias required does not matter. Said tube shows no more glow. The Zerre comes from the Reverbröhre, sick oda? For Zerre no Rev. Also, the recording output is not a preamp out, but a power-reduced power amp out. Paul Rivera; Jack Daniels, Have today TAD ordered, which should make me an offer about the necessary components. For the time being, I will only have the damage repaired. I'm still waiting with other changes. 
Just got from bluesfreak, thx, good info = bad news, But, s is wise. 
Best regards 
Hari




Smoke165
# 14

Had just flew over the pictures, thought only that would be 12ax7. But of course, that's the end pipes. 
Otherwise: is just an old amp, and there you have to wait and wait. Of course you do not want to, but you should always plan with such a purchase, especially if they have not been recently checked.





haqri1220
 # 15


Well, with a set of tubes, I've expected clever man yes. But that it degenerates to the project ......... I wanted the amp, I jatzt him. I see it sporty. The box will funze!


Smoke165
# 16


Originally Posted by haqri1220

a yes, with a set of tubes, I've expected clever man yes.


For old crates always plan the Elkos. But now you know that



haqri1220
 # 17

Oh yes, whoever has the damage mocks every description, But I'm in good spirits. I recently pimped my HB ES 35. All self-made. Was a thing of +500 € (crunchy). Now my favorite gitte, open G, slide. 
The Chibsn does the jazz police, 1st row, crossed arms, alright. 
I already found a capable solderman. Know, but I have to do what he should do. Therefore, more tips are taken very happy. For the hitherto countered, which gave me a clearer view, thank you. 
and greetings hari

Smoke165
 # 18



Your Lötman should then only be careful that the Elkos are really empty before he rumpuhlt there in the amp. Does not sound like a real technician to me?

OneStone
# 19


Originally Posted by haqri1220

I already found a capable solderman. Know, but I have to do what he should do.

Then he is an incompetent solderman and you should look for someone else. 


What kind of a kindergarten is this, where to tell you what to fix on your amp? If the guy does not even manage that, then he should keep his finger out of the box because he just has nothing to do in there. And you not too.



haqri1220
# 20


Originally Posted by OneStone

because he just has nothing to do in there. And you not too.

Who has to look for in my amp, is all alone my thing. And please, generalized personal attacks should be avoided. Where do you take the impudence for it? You do not know my claims. My soldering friend has completed HTL, should contribute quali. I would never have my amp repaired in a hi-fi shop. 


Actually, I only wanted tips related to the amp. I have already mentioned that, as you could hopefully read above.



crazy-iwan
# 21


Originally Posted by haqri1220

Who has to look for in my amp, is all alone my thing. And please, generalized personal attacks should be avoided. Where do you take the impudence for it? You do not know my claims. My soldering friend has completed HTL, should contribute quali. I would never have my amp repaired in a hi-fi shop.  
Actually, I only wanted tips related to the amp. I have already mentioned that, as you could hopefully read above.

@ OneStone is the subject, and knows very well the consequences of the work of supposed professionals. Both the consequences for your and other well-being, as well as for the amp. 

So when he warns against having a layman do it, he does not mean it evil, but caring. 

By the way, I can fully support his advice, a degree is not the same as experience ...





michmo1
# 22

I would like to recommend my amp technician who has serviced and repaired my amps. 

Is very capable, knows and priced ok. After I suspect that you are from Vienna in 1220, he would not be so far away from you, since he is at home in 1210 Vienna. 

Happy PM, just get in touch.






bluesfreak
# 23


Originally Posted by haqri1220
My soldering friend has completed HTL, should contribute quali


Only one helps the higher technical school unfortunately little if it comes to tube technology, something is not taught for decades. OneStone is right, there are just too many cloned amps that have been shredded due to ignorance or partly also (studied) stupidity or turned into life-threatening hell machines (I recently had such a case where one had his Marshall repaired due to background noise and the repairman simply the PE wg suspected interference has abgecken but suspected the real cause why the amp then landed with me) .... and in terms of "impudence" I have to say because I turn the hand not who bangs what here what the hell and OneStone (just because of huge experience) just right and says (always) directly out. 
So I would recommend in all attempts of the repair to look for someone who is capable and the principle and the potential sources of danger of such an amp knows and can estimate, a normal electrician but also a DiplIng can sometimes be overwhelmed ...


haqri1220
# 24


Originally Posted by bluesfreak
in normal electrician but also a DiplIng can be overwhelmed here sometimes


That's what it's all about, and I have to orientate myself as much as possible in my environment. I am built in 1954, have always worked in the field of technology, My Lötmann Bj 1952 has probably completed its completion before the invention of the tube (joke). In my 50-year music-making experience, I have already experienced a few soldering iron gods who had built manure. And, who comes from the side, can not have much to say. This should be a forum, not the Inquisition.




Smoke165
# 25


My assessment: at the amp are things to do that only one can get right and who is from the subject and understands what Röhrenamps. If your guy pays attention to the residual cargo and security, he can swap the old Elkos for you, but there will not be more. (If he reads in, vll still works with bias adjust) Since the amp but then anyway would have to Tech, so that's hardly saved, because the tech need for the things and bias not synonymous with extra time. 'M Under certain circumstances, not against "do it yourself," (and certainly not only me) but this nunmal has very clear limits and here I doubt the sole purpose of making myself, because the tech he has anyway and sparing there is hardly anything. ... and otherwise I think everything is said.

68goldtop
# 26



Hi! 

I do not think that Onestone wants to tackle you here personally. 

The rabbit is (mAn) here in the pepper: 

Originally Posted by haqri1220
I already found a capable solderman. Know, but I have to do what he should do


A "capable solderman" does not need any instructions when overhauling such an amp. 
He simply picks up the wiring diagram and its measuring devices and launches

Cheers - 68.

michmo1
# 27




In itself, we have already exchanged by PM and I haqri1220 already forwarded the contact details of my amp technician and in which he is in good hands. 

Of course it is up to him if he uses the services, but it sounded that way.




haqri1220
# 28



Renew multistage condenser and calibrate bias is done by whom, who has already practiced this once, better several times (joke). Especially with Bias but I want to join in, because, as it has something to do with the sound that I want to have. Messtechnik is no reverence for my ear. And, no one should even think of me having fun taking over 600 misguided volts. 
I talked to the technician advised by michmo, laughed, and we are left.


OneStone
# 29


Originally Posted by haqri1220

And please, generalized personal attacks should be avoided. Where do you take the impudence for it? You do not know my claims.

If you say in a figurative sense, "I have a professional mechanic, please tell me what he needs to do to get the brakes working again," then I have every reason to be clear about what I think of such constructs. 
What the Lord has learned and how old he is, I do not care. 

Either he knows what he's doing - Then he should do that. 
Or he does not know - Then he should keep his hands off it. 

I've seen enough devices in forums and with my own eyes that did not work, burned down, shocked the owner, or something that was wet - both in the final stage and in "that could have come to my senses" when you open it and see. 

There you can get upset as you want, you can do what you want and let people work on your stuff, which according to your own statements (!) Have no idea. But you'll still have to live with people like me telling you it's a damn bad idea. Also to prevent imitators, because as a board writer then for such service - Himmelfahrtskonstrukte also takes a responsibility, if one enters into it.








haqri1220
#30


Or he does not know - Then he should keep his hands off it.

Get full on you. But suppose I would not do anything that I'm not sure I would do to others who they are not sure about. I just wanted to collect information. 
Starting from the possible improvement, the evil-sounding distortion circuit. The Elkodesaster resulted only after the theme opening. Then I started exploring my options and gathern info. Never with the view of a VHS soldering course. Nevertheless, I reserve the right to want to know what to do. I leave it to those who can do it. Sending the amp to TAD is not. 
But I've found a Tek near me through michmo and thus also the possibility Bias something for my ear and instrument set. 
Best regards hari








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