Reconditionare amplificator Priboi

[Vizitator viobio]

in scrierea kirilica P=R aveti dreptate 6R(ADU)3C dubla tetroda cu catod comum ,tuburile finale din Pribojul original6P(I)3C tetrodaacum vedeti diferenta?

[Vizitator kaameelis]

6P3C-1 (6R3S-1).............cele folosite in priboi.aici ceva ce m-a inspirat http://www.hot.ee/kaameelis/GU19Priboi/PriboiGU19_2.htm

da ,dar acea schema are alt traf de iesire! calculat pentru GU19,traful acela are alt Rasi Ua este alta ,240v in loc de 420v

Sorry that in English.6R3S-1 and GU19-1 had very close parameters (except bias voltage), in my modification original output transformer is used and GU19-1 is biased for class-A.Modification was done as exercise "how cheap is possible to get decent sound from Priboi"

[VTP]

@kaameelis,I my opinion, Priboj was a very good amplifier in it's kind! Very cheap in comparison with western brands (more of its China made and western price!!!!).It was, also a very good start for DIY improuvement, and that I did some years ago. A little bit of linearization, replace of foil condensers with MKT decent quality, replace of aluminium electrolitics with others with increased value and smaller dimmensions, replace of 10K trimmers. The rest is connected to the estetic part ( a pot instead of the decades, new connectors for loudspeakers and input, 3 inputs, a new face, etc.) But it makes all the money!!!!!!!!!! OK! It could be done more sophisticated, but me, personally, I didn't needed more!Did you know other improvements based on Priboj with very good results??? I think these could be of interest for users of this forum! Thank you in advance!!!All the best and glad to meet you on this forum!

[Vizitator]

@kaameelis, ...Very cheap in comparison with western brands (more of its China made and western price!!!!)...

Foarte ieftin in comparatie cu brenduri vest(mai mult facute in china dar vindute la preturi vestice)

[Vizitator kaameelis]

Did you know other improvements based on Priboj with very good results??? I think these could be of interest for users of this forum! Thank you in advance!!!

Russian forums and home pages (you can read them with Google translator if interested) had numbers of Priboi modifications but it is hard to tell what is good and what is not untill you do this modifications themselves. One example: http://cxem.net/sound/amps/amp38.php (but not very good as I understand)Other (and better) was scheme where anode voltage for 6N6P was 420V, but I did not find the link now. Third was (more than one version exist) with GU-50 tubes in output - http://audioportal.su/showthread.php?t=437All-in-One: "ПРИБОЙ Переделка" to Google searchWith my modification I am happy, specially as I spend for modification only less than 20 EUR + new tubes. Actually I had 2 Pribois, one modified other original from factory. Modified is much, much better.I know that main problem for getting out better sound (Hi-End like) from Priboi is output transformer that many russians modify also.

[VTP]

@kaameelis,Thank you for links!I knew most of its, and I still read Russian without translation. In '60,'70,'80 I was reading curently RADIO magazine.I tried Lihnitzkii variant with interesting results.In this period I'm focused on a pair of loudspeakers using CIARE (Italy) drivers, BR, 3 ways. Then, probably, I'll start to work to another valve amplifier.Succes in your work and all the best!

[Vizitator kaameelis]

I find more Priboi OPT information in my PC, one usenet conversation about Priboi and sheme where 6N6P (or here 6N1P, no big difference) had 420 V anode voltage, zipped in one: http://www.hot.ee/kaameelis//priboi.zip

[Liviu Ianush]

Chiar nimeni nu mai are asa ceva?

Chiar daca postul este mai vechi, in sfirsit si eu sunt posesorul unui Priboj reconditionat, precum stiti de altfel.Multumesc pentru toate sfaturile oferite.Cum a fost "inviat", ca tot vine Pastele, este descris aici:http://www.elforum.info/viewtopic.php?f=205&t=57703

[zal]

Variante de modificare a Priboi-ului:

[Liviu Ianush]

Variante de modificare a Priboi-ului:

Informatii sunt aici, alaturi de mai multe http://tvr.vejas.lt/uploads/schemos/Stiprintuvai/Lempiniai/Pramoniniai/Priboj/

[pusttiu]

am produs si eu unu , traf de alimentare ars, ars si un traf de iesire....lipsa capac de deasupra (care sincer nu stiu din ce e facut....pare sub forma de u ) si topit capacul de dedesupt chiar unde a a ars traful de alimentare. ii lipseste doar un 6r3s-1 care probabil a aomorat tot amplificatorul.... si nu au sarit sigurantele nici de pe intrare 220 nici cea de pe placa de la final.. murdar de zici ca a stat in cocina..revin cu poze ...cind pot sa le fac.

[VTP]

am produs si eu unu , traf de alimentare ars, ars si un traf de iesire....lipsa capac de deasupra (care sincer nu stiu din ce e facut....pare sub forma de u ) si topit capacul de dedesupt chiar unde a a ars traful de alimentare. ii lipseste doar un 6r3s-1 care probabil a aomorat tot amplificatorul.... si nu au sarit sigurantele nici de pe intrare 220 nici cea de pe placa de la final.. murdar de zici ca a stat in cocina..revin cu poze ...cind pot sa le fac.

Capacul superior, un U, este din aluminiu, capacul inferior este de plastic.Faptul ca sigurantele nu s-au ars rapid, dimensionarea lor fiind facuta sa reziste la pornirea aparatului, cand curentii sunt mari, se datoreaza faptului ca, la defectul care provoaca problemele citate, respectiv disparitia negativarii la unul sau ambele tuburi ale unui canal, curentul creste relativ incet, in decurs de cateva minute, suficiente ca transformatoarele sa se arda, tubul sa se topeasca, etc. S-au semnalat si cazuri de incendiu. Astfel, un amplificator bun si-a capatat un renume prost si a fost ostracizat ca "un lucru rusesc, deci prost!"

[Vizitator viobio]

se poate modifica schema care asigura tensiunea de negativare ,nu stiu de ce nu s-a gindit nimeni pina acumdaca tot restaurati asemenea ampuri de ce nu incercati sa eliminati si "micile defecte ale schemei"cu putina imaginatie ! trebuie sa evitam ca tensiunea de negativare sa mai plece din cursorul semireglabililorcel mai bine este sa folosim semireglabil intre -Un si masadaca din intimplare se intrerupe semireglabilul ,toata tensiunea de negativare ajunge in grilele tuburilor si le blocheaza,adica vom avea un curent mic prin eleeu la ampurile de chitara am adoptat acest sistem de cam doi aniam si eu doua trafuri de iesire de Priboij,multumesc dl Mateescu!!in octombrie 2012 se fac TREI ani de cind ma chinui sa fac doua monoblocuri cu ele!!!!am toate componentele ,trafuri de alimentare socuri de filtraj,etc,dar nu am timp!!!!!!!!!eu intentionez sa folosesc urmatoarele tuburi1XEF806S TELEFUNKEN1XE80CC SQ PHILIPS2XKT120 TUNGSOLsucces si multa IMAGINATIE!!!

[blue]

Sigur ca da, aceasta este solutia logica !

[Liviu Ianush]

Eu am pus o rezistenta de 47k intre cursor si capatul cald. Daca se intrerupe cursorul, ramine rezistenta si nu dispare negativarea.