swr workingmans 15

[J M Fahey]

de preamplifier de piept alleen bij hoge gain

the preamplifier the beeps only at high gain

And what does it mean? I understand the words, but not what you are trying to describe.
What kind of sound is a "beep"(piept)?
Is it hum/hiss/oscillation/some audio signal you are injecting?
And *how* do you hear that "beep"?
Explain things using more words, giving greater detail.

op de uitgang van de eindversterker heb ik geen spanning de transitor Q10 and Q4 zijn niet defect 0.20 mv

at the output of the amplifier I have no voltage to the transistor Q10 and Q4 are not defective 0.20 mv

I understand the output transistors are not bad, and you have offset 20mV.
Well, that is fine.
BUT YOU DO NOT ANSWER WHAT WE ASK YOU.

ik hoor de brom ook als de eindversterker aan staat met gain dicht

I hear the hum even when the amplifier is turned on with gain close

So you hear hum even with gain closed?
What happens if you lift one leg of C13? Do you still hear hum?
Slight hum that can only be heard close to the speaker or strong hum which can be heard in the next room?

r29 r42 geen verbinding met masa maken

r29 R42 can not connect to make masa

Again I understand the words, but not what you are trying to describe.
Are R29/R42 connected? You want to connect them to ground?

en de voorversterker heb ik hier nog op 15 volt staan

and the preamplifier, here are 15 volts

So the preamp has 15V rails. Fine, but ... are you feeding it external 15V or is it fed from the amplifier rails through R1 and R2?

geluid input voorversterker geluid erg slecht c13 en deze is van de eindversterker los gemaakt

audio input preamp sound very bad c13 and it is disconnected from the power amplifier

So the preamp sounds bad. What is bad? Distorted, hums, what?
PLEASE ANSWER THESE QUESTIONS AND EARLIER ONES.
Separate questions as I did and answer them one ny one.
If I ask you "Please answer what voltage do you measure on each end of 2.7K" paste my question and right below it the answer to that question.
And so on.
Thanks.

PS: and I *still* do not know what is the amp defect:
does it hum even with volume on 0?
is it mute?
it sounds but distorts?
Translators can help with *words* but they won't translate what you do not say or if you offer confuse information .
Thanks.

[J M Fahey]

i have new test
i have disconnted the premaplifier and can hear a brum
the amplifier works well only with brum

So the amplifier works properly but hums audibly?
How loud does it hum?
And if you reconnect your preamplifier; does it hum more or less than without it?
And if you play your bass, can you hear it, but with some hum, or is it horribly distorted?

[kip[py]

het maakt geen verschil voorversterker aan of uitzetten
de brum is goed hoorbaar
als je geluid op de voorversterker zet wordt de brum minder
echter de gain vol open dan klapt de eindversterker( loudspeaker) helemaal

[J M Fahey]

it makes no difference preamplifier on or off
brum is the audible

So with preamp off , you still hear hum?
OK, leave preamp off meaning one leg of C14 open and measure hum voltage at speaker terminals.
Set your multimeter to AC volts and vary scale until you get a reading, then post that value here.
As in: "I get xxx Volts (or Millivolts) AC of Hum"

and your sound at the preamplifier converts the brum less

Do not understand what you mean.
You first said that preamp on or off makes no difference to Hum, now you say that *some* sound (what sound, your bass playing?) makes hum lower (less "brum") ?
Please explain *this* clearly, we can not go on if you contradict yourself.

However, the gain full flips open the amplifier (loudspeaker) completely

Sorry, but I do not understand what you mean.
Are you trying to explain what happens when you fully open the gain? Meaning gain or volume on 10?
NOW we are working *only* with the power amplifier *and* with one leg of C14 open.
Please answer exactly what I ask in Red.

Or, as Google Translate would say:
OK, laat voorversterker uit wat betekent dat een been van de C14 open en maatregel brom spanning op luidsprekeraansluitingen.
Stel uw multimeter op AC volt en variëren schaal tot je een reading, dan hier posten die waarde.
Zoals in: "Ik krijg xxx Volt (resp. millivolt) AC van Hum"

[kip[py]

ik heb c14 los van massa R1 R2 geen verbinding no connection naar c1 en c2 dus voorversterker uit
meet ac 0.120 volt
meet ac met voorvertserker aan connectionpreamplifier 0.218 volt
ik heb nu niets aan gesloten op de gitaar versterker

[J M Fahey]

Dear kippy.
I asked you to write in Dutch because your English is very poor ... but your Dutch is poor too. Sorry.
When a Computer Translator is used, you must be very careful to choose words, and write them *perfectly* (the computer can not guess like a human) ... and you must not mix 2 languages on the same phrase, it confuses the computer.
You just wrote:

ik heb c14 los van massa

I have c14 independent of ground

Fine.
I made a mistake, we were talking about C13, the power amp input capacitor, I earlier asked you to lift one leg to separate preamplifier and power amplifier.

R1 R2 geen verbinding no connection naar c1 en c2

R1 R2 no connection no connection to c1 and c2

here you wrote part in English.
OK, connect R1 and R2 to C1 and C2, so we get the normal supply connection.
If you feed that preamplifier with an external transformer, *you* may be injecting hum.
A lot of it.

dus voorversterker uit meet ac 0.120 volt

So preamplifier off 0.120 volts ac measurement

So with preamplifier disconnected you measure 0.120V AC *at the speaker output*?
Well, it may be quite annoying in a bedroom, or recording, but when playing live, with a band, it should be bearable.
It is *not* the very strong hum that appears on a shorted power amplifier, like we believed earlier.

meet ac met voorvertserker aan connectionpreamplifier 0.218 volt

Here you spell one word bad, write two words in English and join them into a single word that means nothing for the computer. Oh well.
Back to the amplifier, now you connect the preamplifier and measure 0.218V AC *at the speaker output*?
Well, that is somewhat more annoying, but still not *that* bad, the amplifier is usable.
Please connect it back as original: feed the preamplifier through R1 and R2, connect R13 again, put all controls on 0 and re-measure the hum level at the speaker output.
Then, short circuit R33 (68K) with a small piece of wire, and re-measure hum AC voltage at the speaker output.
I *only* want the answers to questions written in green.

ik heb nu niets aan gesloten op de gitaar versterker

I have nothing now to concluded on the guitar amp

Ok, please answer the green questions.
Thanks.

[kip[py]

connect R1 and R2 to C1 and C2 OK
with preamplifier disconnected you measure 0.120V AC *at the speaker output*? YES
now you connect the preamplifier and measure 0.218V AC *at the speaker output*? YES
Then, short circuit R33 (68K) with a small piece of wire, and re-measure hum AC voltage at the speaker output.
ik begrijp niet wat je bedoel hier mee
een draadje op 68k en dan naar ???

[kip[py]

i have test with my scope and see from PGND to BR i see the 50 hz brum
ik heb en test gedaan met mijn scope en zag toen van PGND naar BR 50 hz brom

[J M Fahey]

connect R1 and R2 to C1 and C2 OK OK
with preamplifier disconnected you measure 0.120V AC *at the speaker output*? YES OK
now you connect the preamplifier and measure 0.218V AC *at the speaker output*? YES OK

Then, short circuit R33 (68K) with a small piece of wire, and re-measure hum AC voltage at the speaker output.
ik begrijp niet wat je bedoel hier mee een draadje op 68k en dan naar ???
I do not understand what you mean here along a wire at 68k and then to???

To short R33 means a wire from end to end, so we kill any external hum.
Do it and measure Hum voltage at the speaker output.
Also look in your oscilloscope, is it lower hum now?

[J M Fahey]

i have test with my scope and see from PGND to BR i see the 50 hz brum
ik heb en test gedaan met mijn scope en zag toen van PGND naar BR 50 hz brom

You should have written een , not en, the translation is better.
Corrected, it means:

I did a test with my scope and saw from PGND to BR 50 hz hum

Yes, *of course* you will see around 38 V AC 50Hz "hum" there, it is a power transformer secondary.
I want to know what V AC hum voltage you measure from W14 OUT to W15 POWER GND , after you short circuit R33 .
Thanks.

[kip[py]

ok i have short R33 means a wire from end to end and see with mulitimeter 0.08 volt ac
i tink the brum come from the pre ampilfier
i connected a head amplifier from c13 and gnd and can hear the 50 hz brom c13 are no connected with the amplifier

oke ik het r33 verbonden naar massa en zag op mulitmeter 0.08 volt ac
ik denk dat de brom van de voorversterker komt
ik heb een hoofdtelefoon versterker verbonden met c13 en maasa en hoor daar de 50hz brom de eindversterker is niet verbonden met c13

[J M Fahey]

Please check what you write carefully, you still have typing mistakes.
You are making *me* learn Dutch !!!
It reminds me of my old time Short Wave Radio Listening, when I used to listen to Radio Hilversum every night.Radio Netherlands Worldwide - Wikipedia, the free encyclopedia

ok i have short R33 means a wire from end to end and see with mulitimeter 0.08 volt ac
i tink the brum come from the pre ampilfier
i connected a head amplifier from c13 and gnd and can hear the 50 hz brom c13 are no connected with the amplifier

oke ik het r33 verbonden naar massa en zag op mulitmeter 0.08 volt ac
ik denk dat de brom van de voorversterker komt
ik heb een hoofdtelefoon versterker verbonden met c13 en maasa en hoor daar de 50hz brom de eindversterker is niet verbonden met c13

The correct translation is:

okay I r33 connected to ground and saw multimeter 0.08 volts ac.
I think the hum comes of the preamp.Good- That is what I suspected.

I have a headphone amp connected to c13 and ground there and hear the 50hz hum.
the amplifier is not connected to c13.Good, that confirms it

Now we move backwards, towards the input, to find the humming amplification stage.
We will re-connect C13, disconnect the short circuit across R33 (yes, you will hear hum again ) .
Now we will test the compressor, which is the last preamplifier stage.
I *hope* you did not touch or move R74, the Limiter Adjust Preset Potentiometer.
For now, set all amplifier controls to 0, confirm that again you have hum and tell me what is the AC voltage at the Speaker output.
This will be our reference point.
Then I will suggest some tests to be made.
We now know that the *minimum* Hum we will get will be close to 0.08 VAC, which is not bad.
One last doubt: what VAC scales does your Multimeter have?
Only 2 (as in 200V AC and 750VAC) or you have many, down to 200mVAC?
The first type will not be enough, you need a sensitive multimeter.
Thanks.

[kip[py]

ok R74 where can i find it on pcb ? or housing
i have a velleman DVM345DI mulitimeter voltage setting automatically
i have see 0.220 ac with connect c13 preamplifier

oke R74 waar kan ik deze vinden op de print ? of behuizing
ik heb ee velleman DVM345DI mulitimter voltage gaat automatisch geen instellingen dus
i zie hier 0.220 ac op luidspreker uitgang en c13 is weer door verbonden

radio 3fm heet het tegenwoordig en is er nog steeds

gr. ruud

[kip[py]

and i have here see one Potentiometer on this pcb
en ik zie maar 1 potmeter op de print

[kip[py]