Hey gang, so I have this old valve radio which has an ecc83 preamp tube run as a two channel stereo and then there are ECL86s for each of the channel in the power amp section.
Now, although it somewhat worked while still in the wooden enclosure, something got damaged while i was taking it out. I don't really feel like bothering to measure all the old dusty buggered semiconductors, also the construction of the multiband radio receiver is a big mess.. or maze.. or both so to get to the board where the amplifier section is mounted is extremely inconvenient, that is why i have decided not to try to mend it but rather salvage what i know is good and functional and build a new simpler amp around those parts in a fresh chasis: the transformers, tubes and sockets and the amp board.
Now my question.. is it possible to rewire the two triodes of the ecc83 as two gain stages and then run it to one of the ecl 86's in the power section?
And if so, is it possible to wire a gain pot? The radio obviously only had a volume one, treble, bass (and stereobalance which i would remove bcs i do not intend to use it as a stereo amp).
I do have a full schematic and parts data sheet. But I am seriously considering just using the ecc83, one ecl86 and just point to point wiring it bcs there is a lot going on the original pcb and there are leads and switches all around the place bcs of the multiband radio receiver..
I know I should probably just buy brand new parts for a simplified princeton or whatever 🙂 but at the same time I would like to give new life and purpose to this old junk which has been lying in the attic for decades. And I do want to build from these parts bcs I know it sounded pretty good considering its age and state and the fact those werent even guitar spekers.
Here is the maintenance manual with the schematic of the radio at the end http://www.oldradio.cz/schemata/ts538sn.pdf
Now, although it somewhat worked while still in the wooden enclosure, something got damaged while i was taking it out. I don't really feel like bothering to measure all the old dusty buggered semiconductors, also the construction of the multiband radio receiver is a big mess.. or maze.. or both so to get to the board where the amplifier section is mounted is extremely inconvenient, that is why i have decided not to try to mend it but rather salvage what i know is good and functional and build a new simpler amp around those parts in a fresh chasis: the transformers, tubes and sockets and the amp board.
Now my question.. is it possible to rewire the two triodes of the ecc83 as two gain stages and then run it to one of the ecl 86's in the power section?
And if so, is it possible to wire a gain pot? The radio obviously only had a volume one, treble, bass (and stereobalance which i would remove bcs i do not intend to use it as a stereo amp).
I do have a full schematic and parts data sheet. But I am seriously considering just using the ecc83, one ecl86 and just point to point wiring it bcs there is a lot going on the original pcb and there are leads and switches all around the place bcs of the multiband radio receiver..
I know I should probably just buy brand new parts for a simplified princeton or whatever 🙂 but at the same time I would like to give new life and purpose to this old junk which has been lying in the attic for decades. And I do want to build from these parts bcs I know it sounded pretty good considering its age and state and the fact those werent even guitar spekers.
Here is the maintenance manual with the schematic of the radio at the end http://www.oldradio.cz/schemata/ts538sn.pdf
The ECL86 already has a high gain triode inside. Two more stages would create a huge gain and the related issues. What kind of signal source would you have? You can make a single tube single ended amp with an ECL86.
To be honest in page 24 you have a separate PCB board with the stereo audio amplifier. You can probably throw away the radio part, and just use that board. Adding a volume control there is very easy.
PS You do have a volume pot already, the left one. I'm not sure about the pot on the right, seems like also a volume control, but weird, and could be part of the tone control instead.
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Thank you for your reply 🙂
That's exactly what I ment to do.. take the amp portion out .. but there is something wrong with one of the channels.. and alas something broke or shorted when I was pulling it out. to identify what exctly would be a challenge for sucha noob as i am. That's why I have more or less decided now to do a point to point wired ecc83-ecl86 amp for guitar. That ecl86 has a lot of gain is good news for me..I understand the ecc83 too. I like a lot of distortion 🙂 But as it was in the radio i ment to use ti with a distortion pedal.
The poit on the right is the stereobalance - balance between one 86 and the other 86 - between left and right. That's a pot that I would have removed.
My bad...I'm always thinking about HiFi, which is the wrong thinking when dealing with guitar amps.
All I know about guitar amps is that you need a lot of gain, and some distortion is desirable.
I have been staring at it for hours dude.. i have been also trying to isolate or track the signal path from the gramophone input (which i would use as the guitar input) to the ecc83 which i might have but i dont see clearly what happens to the signal after it.. does it go to the pin 1 of the E5 -86 ? then i am lost completely.. there is so many connections and there are so 15 switches on the radio all kinda interconnected... so the schematic to my noob eyes is a maze. That's why i might really and up point to point wiring only the two tubes. Even though I first thought what you suggest would be fairly easy..
Now, if i do a basic ecc83 + 1 ecl86 with Volume, treble and bass and possibly gain? What would be some logical caps and resistors tu use? I have found some data sheets and even an ecc86/12ax7 preamp schematics, but it is not clear to me how to connect that to the 86 power tube. and how to build a tone stack.
Could i do , for instance something like this (with the two triodes?):
and then from the out it would lead to the IN pin of the ecl86?
The voltages are way different tho.. would it make a big difference in sound? or would lower voltage (in my case) than the ona in the picure just mean fewer Watts?
could this kinda preamp be just put in front of something like this (i understand the little bullseye symbol means an input)?
Sorry about such ignorant questions 🙂 I am not educated in the field. Thank you.
Asking questions is the right thing to do 🙂
I would recommend moving the thread to the "Instruments and Amps" thread. There are a lot of discussions about guitar amps, you will find the right advice. This thread is mostly about Hi-Fi valve amplifiers.
About the schematic you suggested, you got the right idea, but the execution is not right. I would recommend first to have a good reading about the basics, for example:
https://robrobinette.com/Reading_Tube_Amp_Schematics.htm
There is even an schematic of a Fender amp that could be the base for yours (I pointed out where can you use your ECL86):
You could even use both channels with two speakers, more power. In total you will need two ECL86s and one 12AX7.
This is just a suggestion of a person not familiar with guitar amps, it would be better if you follow the advice of someone who knows this well.
Regards,
Jose
I would recommend moving the thread to the "Instruments and Amps" thread. There are a lot of discussions about guitar amps, you will find the right advice. This thread is mostly about Hi-Fi valve amplifiers.
About the schematic you suggested, you got the right idea, but the execution is not right. I would recommend first to have a good reading about the basics, for example:
https://robrobinette.com/Reading_Tube_Amp_Schematics.htm
There is even an schematic of a Fender amp that could be the base for yours (I pointed out where can you use your ECL86):
You could even use both channels with two speakers, more power. In total you will need two ECL86s and one 12AX7.
This is just a suggestion of a person not familiar with guitar amps, it would be better if you follow the advice of someone who knows this well.
Regards,
Jose
. 02 is 0.02uf. 600 is the maximum voltage. A modern common equivalent will be 0.022uf 630V.
And yes, that was my suggestion. The ECL86 already has a high mu triode inside.
Or you could replace the ECL86 with an EL84, and use both 12AX7 triodes. There are endless possibilities.
But you already got the ECL86s, maybe better to stick to that.
PS Errr... Your previous post I was answering disappeared...
And yes, that was my suggestion. The ECL86 already has a high mu triode inside.
Or you could replace the ECL86 with an EL84, and use both 12AX7 triodes. There are endless possibilities.
But you already got the ECL86s, maybe better to stick to that.
PS Errr... Your previous post I was answering disappeared...
yes sorry, i removed it because i had already found out from the page you suggested 🙂
now i am looking at the princeton schematic there.. daaam there is a lot going on.. they used triodes of those 12ax7s for like four separate purposes.. 😀
they did not fudge around 🙂
Now .,. you are suggesting el84s but I would like to work with those tubes i have in the radio, so the 86s if possible.
In the princeton there is one triode of an 12ax7 used as a phase inverter for the following tubes to be push pull, do you think it would be possible to use (in my case) the first ecc83 triode for preamp then put a tone stack or just volume and then its other triode to do the phase inverting so that i could use both 86s as push pull? in my radio they work as separate stereo channels one for each side..
EDIT : ... yes.. looking at the DELUXE now and it is just in there 😀 sorry.. and thanks a lot for the page.. 🙂 its so good !
now i am looking at the princeton schematic there.. daaam there is a lot going on.. they used triodes of those 12ax7s for like four separate purposes.. 😀
they did not fudge around 🙂
Now .,. you are suggesting el84s but I would like to work with those tubes i have in the radio, so the 86s if possible.
In the princeton there is one triode of an 12ax7 used as a phase inverter for the following tubes to be push pull, do you think it would be possible to use (in my case) the first ecc83 triode for preamp then put a tone stack or just volume and then its other triode to do the phase inverting so that i could use both 86s as push pull? in my radio they work as separate stereo channels one for each side..
EDIT : ... yes.. looking at the DELUXE now and it is just in there 😀 sorry.. and thanks a lot for the page.. 🙂 its so good !
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Interesting idea 🙂 However, I am not sure how much life these elc86s still have in them so I don't know if I could even ask such a price for them to get those 84s 🙂 I would be possibly open to a trade for used ones.. are they really highly saught?
They were quite commonly used and they are no longer made, so there is an ever dwindling supply. Not big bucks, but they are popular on auction sites.
The Valve Wizard site is a good place to start with basic guitar amp circuits. He used to have PCBs for sale, probably the easiest route to a working amp.
The Valve Wizard site is a good place to start with basic guitar amp circuits. He used to have PCBs for sale, probably the easiest route to a working amp.
@Klingy : have a look to the MAGNATONE guitar amp schematics (i.e. Model 411) : they much used the 6WG8 / ECL86 in SE or PP...
My RADIO-TONE (below, DIY) uses a single ECL86 in a super small but standalone package :
Here is the schematic - derived from the Magnatone model #411, by the way :
Here is a sample of the Radio Tone. Guitar = Squier Std Strat, with a touch of EHX Cathedral Reverb.
T
My RADIO-TONE (below, DIY) uses a single ECL86 in a super small but standalone package :
Here is the schematic - derived from the Magnatone model #411, by the way :
Here is a sample of the Radio Tone. Guitar = Squier Std Strat, with a touch of EHX Cathedral Reverb.
T
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@tubelectron Aaaawwwww 🙂))) thats soooo cute 🙂 kinda packed in there..but well.. compact.. doing its intended job well 🙂 I love it !!! And thanks for the schematic 🙂
Also it sounds very nice 🙂
Also it sounds very nice 🙂
The volume at the input of the guitar amplifier is not common. Also, the tone control . There is tow 220 Ohm resistor in series in the power supply... It is not very good as a filter.