Re: Reel to reel tube recorder Geloso G258, problem
Good morning guys.
The uscita headphones is for external speaker.
The red trimpot is for adjusting the sensitivity of EM84. Does not effect the recording or playback mode.
It is somehow strange the schematic to has errors because in the next model G268 how appeared two years later the schematic has the same values.
Im was thinking to change them again with new ones.
What you believe, to use the schematic capacitors or the factory capacitors?
The so big difference...
Lef de art
Member
Last Activity: 11-20-2019, 11:42 AM
Joined: 10-19-2019
Location: Cyprus
-
Re: Reel to reel tube recorder Geloso G258, problem
No i haven't.
The voltage in the schematic is different with the voltages in the chassis.
In the schematic the capacitor appear as 50k/250v and in reality was 50k/350v.
I have changed 11 papper capacitors.
The 8 capacitors are ok and the schematic values are very close with the chassis values.
But in the 3 i have mentioned the chassis value does not even close with the schematic value. That way was . I have changed them by the chassis values not by the schematic values. ...Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Trying to configure what can be happen, and to exclude the possibility to have read wrong any capacitor inscription i decide to compare the removed capacitors with the inscription in schematic.
Comparing them i have found 3 big difference.
In the schematic in the chassis
2K/600v 0.02uf/150V
2K/400V 0.05uf/350V
5K/400V 0.005uf/50V
The inscription on them is very clear. You can see in the pictures.
...Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
The 0.5uf/150v capacitor was replaced with 0.56/250v.
I haven't change the 4 commutator capacitors because are polystyrene capacitor and i know they don't really get bad through time. So this 4 capacitors are the same with the before (good low frequencys) and the after (bad low frequencys) situation.
The red trimpot is for changing the magic eye (EM84 valve) sensitivity . Does not effect the low frequencys or the sound generally.
Just to mention that the amplifier works nicely.
The...Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
I think i have confused you with my bad English
I have lost bass from my new recordings after capacitor change.
The bias head it is cleared . Yes in playback mode works perfectly.
Only in the recording mode , records with lower bass.Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Yes i have checked it . Is not from bias, because the new records don't have bass. The playback process with the old records is ok.
I believe that the problem is in some capacitors close to mic input. I must rechange them. Perhaps one of them or more don't work correctly.Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Yes i have cleaned it.Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
The difference is on recording high frequencies .
The recording has lost high frequencies.
The playback mode with old capacitors recordings sounds ok.Last edited by Lef de art; 11-07-2019, 04:54 AM.Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Thanks Redwire. I will check them today.
The electrolitic capacitors work all good because i have changed them all in first stage and i then the recording quality was ok.
After i change all the papper capacitors the recording high frequencies are very weak.
And the recording sound has more treble.
But the changes are in recording .Last edited by Lef de art; 11-07-2019, 04:53 AM.Leave a comment:
-
Re: Different capacitors in the sassi and different values in the schematic !
Comparing the recording sound i have now with the sound i had before changing the capacitors i have the filing that i have lost enough bass, low frequencys.
As it is normal in the replacement capacitors process it wasn't easy to find the exactly value in capacitors. So some changes was made...
There is any chance the following replacements to be wrong?
What is your opinion?
0,005uf / 150v replaced with 0.0056 250v
0,002uf / 400v replaced with 0,0033 400v...Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Comparing the sound i have now with the sound i had before changing the capacitors i have the filing that i have lost enough bass, low frequencys.
As it is normal in the replacement capacitors process it wasn't easy to find the exactly value in capacitors. So some changes was made...
There is any chance the following replacements to be wrong?
What is your opinion?
0,005uf / 150v replaced with 0.0056 250v
0,002uf / 400v replaced with 0,0033 400v
0,025uf / 300v replaced with...Leave a comment:
-
Re: Different capacitors in the sassi and different values in the schematic !
Yes it's polystyrene capacitor. So it is pf
Leave a comment:
-
Re: Different capacitors in the sassi and different values in the schematic !
Or this capacitor . Is 500v , 5% tolerance
The 200 in what unit is ?...Leave a comment:
-
Re: Different capacitors in the sassi and different values in the schematic !
A capacitor with 250/5 inscription, what value it has ?
I know the 5 is the tolerance but the 250 what it is ?Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Thanks Redwire .
It is the lamp. I have changed the position with the other 12AX7 and the phenomenon occurred in the same lamp but this time in the different positions.
As i understood is not something important. Does not mean the bulb is defective so everything is okLeave a comment:
-
Re: Different capacitors in the sassi and different values in the schematic !
Thanks again Redwire
Leave a comment:
-
Different capacitors in the sassi and different values in the schematic !
Hello guys.
Recently i finished my first restoration in a 61 years old tube reel to reel recorder (Geloso G258) .
Thanks God the process ended positively and the recorder works again very good.
In this process i met a big problem by trying to figure what value in capacitors to use.
I say this because all the capacitors excluded the electrolitic had different values from the capacitors in the sassi !!!
Not one or two capacitors. It's about 12 capacitors !!!
For sure i have the correct schematic.
At the end i have used... -
Re: Reel to reel tube recorder Geloso G258, problem
Hello again guys.
I have changed the electrolitic and papper capacitors and the problem is resolved. The recording and erase process now works normally.
But i have noticed that when i power on the system, the middle lamp 12AX7 , lights really much for 1/2 seconds , then decrease and remain in the normal light as the other lamps .
I believe it is over voltage in first 2 seconds because of some capacitor.
Any idea ?
This happens only when the system is off for at least...Last edited by Lef de art; 11-01-2019, 07:07 AM.Leave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Thanks Budm.
I have ordered them and i wait to receive them so i can start the replacing process.
It will take some time to receive them but i will update the forum with the processLeave a comment:
-
Re: Reel to reel tube recorder Geloso G258, problem
Is a important capacitor for the system ?
It must be changed or does not really matters ?
It is a papper capacitor so for sure does not work correctly any more....Leave a comment:
No activity results to display
Leave a comment: