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New Vintage Pickup - What Do You Do?

dogface1956

dogface1956

Need it now!!!!
Hello,

I have not posted to Vintage very much, but have a bunch of vintage receivers and integrated amps. I am not all that technical, but know my way around with a soldering iron and can with the help of a service manual do basic trouble shooting.

When you get get a new "vintage" find what is the first thing you do? Do you plug it in and give it a spin? Do you deoxit it, give it a general cleaning and check the DC-offset and before you give it a spin?

How much risk is there to plugging it in and giving it a spin?

After spending more time on Vintage I am wondering if my plug it in and play it is a good idea, seems that there is more that can go wrong then I realized. I have not had any speakers blow up, but maybe I have just been lucky.

Thanks, this is a great resource and I am sure I will have more questions.
 
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I tend to plug it in, check that there's no 230V in the case (yeah, don't ask me why), see if it lights up and then ckeck the DC offset before plugging in a set of test speakers and giving it a go! After that, it's cleaning from the inside out and maybe recapping.
 
The techs say, if its been sitting for a long time, it needs to be powered up slowly, as to not blow any caps. There is a machine you can buy to do this, and im sure many great vintage pieces have been saved by using it.
 
The machine is called a variac, and some say it's not as useful for this on a SS unit as it is on a tube unit.

If you haven't got a variac you can make a DIM BULB TESTER. (Search DIM BULB TESTER in FORUMS).

If the unit hasn't been run for 6 months or more, then put it on a variac OR a Dim Bulb Tester and bring it up slowly to reform the caps. For tube stuff i start @ 40WATT Bulb and check for BRIGHTNESS of the bulb, if it blooms and dies off, then continue. If it stays lit, SHUT IT DOWN NOW!!!!! There's a short in the unit. Up the wattage to 60W in two or three hours. If you get no smoke, or no caps bulge, keep upping the wattage to 75W then 100W. Leave it for an hour @ 100W. Then if no problems go ahead and try direct connect.

Solid State units I halve the time on the bulb tester and start it up direct. This helps the caps in that they aren't getting a FULL JOLT the 1st time and are being brought up gradually.

If you get smoke or bulging caps at any time, SHUT IT DOWN!!!. DO NOT ENERGIZE until the problem has been solved(generally new caps).

If it was running when you picked it up, then pull it apart, CLEAN EVERYTHING! De-Oxit All controls. Change the cord if needed.

DO NOT USE ANY CHEMICALS on the TUNING CAPACITOR. Vacuum or blow with Air around it.

After all this, plug it in, and check your DC offset or Bias settings. If everything is fine, use the receiver. In the meantime order new Electrolytic capacitors. the originals are pretty well dried out and can be ticking bombs. Replace the 'lytics as you find time on the bench. Shouldn't take more than an afternoon or evening per unit
depending on the unit.

Others should/will pipe up and give better directions/ reasons. I'm still learning and would be considered a nOOb.

Have fun, BE SAFE, and Welcome to the MADHOUSE!!

Larry
 
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jhoyt said:
Larry, that's excellent! :thmbsp:
Click to expand...

+1, I had been wondering about how dim-bulbs worked, or how to use them. That was a great description:yes:.

As mentioned, the best thing is to initally bring it up slowly, and as mentioned, this isn't as useful for solid state, but still important. If nothing is wrong, that's good news, many solid state things if well kept, are still doing pretty well. I hope you get everything up and running without any problems:thmbsp:.
 
Another Dim-Bulb user .

I always open it up and do a visual , then with an Ohm meter check to see if there is a short to chassis on either side of power cord working the PWR switch .
then check the fuse or fuses to see if correct . You would not believe what I've found in place of fuses . Besides aluminum foil and box staples .

Then Dim-Bulb time with a 60W bulb and a prayer .



Barney
 
Thanks for the info

As I mentioned I am pretty new here and have learned on this forum. I will be making a dummy bulb to test my new systems. I just go a Scott Receiver today which I will take apart, clean-up, measure and test before connecting it up to one of my systems.
 
Sam Cogley said:
I've even used my dim-bulb tester to check out a Variac! :D
Click to expand...

A good idea, just recently, I nearly had a variac weld itself to a outlet because the old power wire finally split. Scared me half to death, but am really glad nothing too bad happened.
 
33&athird said:
A good idea, just recently, I nearly had a variac weld itself to a outlet because the old power wire finally split. Scared me half to death, but am really glad nothing too bad happened.
Click to expand...

One of mine started smoking. I think it's just dirty, but I've never gotten around to working on it.
 
Understand that some amps need the help of a regulated supply to limit bias current flow, and bringing them up on a Variac or dim-bulb tester is a really bad idea. For instance, either one is a great was to kill a VFET amp.

Most SS gear I just plug in and go. If something blows, it damn sure was gonna blow anyway. But do check DC offset before you connect speakers.
 
There's a great thread with info on checking DC offset in a sticky at the top of the Vintage Solid State forum here. Great info there.
 
EchoWars said:
Understand that some amps need the help of a regulated supply to limit bias current flow, and bringing them up on a Variac or dim-bulb tester is a really bad idea. For instance, either one is a great was to kill a VFET amp.

Most SS gear I just plug in and go. If something blows, it damn sure was gonna blow anyway. But do check DC offset before you connect speakers.
Click to expand...

THAT's going in the memory banks!
 
dogface1956 said:
Hello,

I have not posted to Vintage very much, but have a bunch of vintage receivers and integrated amps. I am not all that technical, but know my way around with a soldering iron and can with the help of a service manual do basic trouble shooting.

When you get get a new "vintage" find what is the first thing you do? Do you plug it in and give it a spin? Do you deoxit it, give it a general cleaning and check the DC-offset and before you give it a spin?

How much risk is there to plugging it in and giving it a spin?

After spending more time on Vintage I am wondering if my plug it in and play it is a good idea, seems that there is more that can go wrong then I realized. I have not had any speakers blow up, but maybe I have just been lucky.

Thanks, this is a great resource and I am sure I will have more questions.
Click to expand...
I always connect new stuff up to a dim bulb tester first right after my visual inspection to see if I find any obvious damage like rust or pitting that suggests it is not safe to power up. The Dim Bulb tester saves your device if it has an internal short. The bulb will glow bright if their is a problem. The bulb will glow bright for a few seconds as the filter capacitors power up and the protection circuit comes in. Don't try to tune or use the receiver when the dim bulb is connected. If the receiver passes the dim bulb test I turn it on at full mains power to the time it takes me to test all its features. Before plugging it in I connect two speakers. 4 if I have them a cassette deck and a CD player into the AUX, a turntable into the correct phono input. magnetic or ceramic. Then I power the receiver on just long enough to test each component. Once I am sure the A and B speakers work, tape deck works, aux works with the CD player. I note any burnt out bulbs, noisy or broken pots, switches and or knobs. I give it the smell test if nothing smells great. Look at your power cord to insure it is not brittle or broken anywhere. This is a good start. many others likely have additional things you can do to stay safe.
 
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