4th Oct 2010, 10:11 am | #81 |
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 10:36 am | #82 |
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Re: Leak Delta 30 Amplifier - One Channel Down
Help! Will 1/2 a watt be sufficient for R15?
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4th Oct 2010, 10:49 am | #83 |
Octode
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Re: Leak Delta 30 Amplifier - One Channel Down
Yes, a 470K 1/2W resistor will be fine to replace R15.
John |
4th Oct 2010, 10:51 am | #84 |
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 11:17 am | #85 |
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Re: Leak Delta 30 Amplifier - One Channel Down
Nothing like Maplin, Tandy, Radio Shack or Dick Smith Electronics in Japan then? That surprises me.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
4th Oct 2010, 11:46 am | #86 | |
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Re: Leak Delta 30 Amplifier - One Channel Down
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I don't live in Tokyo though. Far from it. I am asking if anyone I know in Yokyo is in the Akihabara area this week but all in all, if I buy it from the UK, I know I am getting the right thing and best of all I can do it all by myself. |
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4th Oct 2010, 11:50 am | #87 |
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Re: Leak Delta 30 Amplifier - One Channel Down
Right. I checked ever other resistor on the board and they are all good with the possible exception of R27 (3.3k) reading 3.8K and R25 (3.3K) reading 4.02K. These are both bigger wire wound type resistors. Is that anything to worry about do you think?
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4th Oct 2010, 11:54 am | #88 |
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Re: Leak Delta 30 Amplifier - One Channel Down
When you measured R32 in circuit was one of your probes connected the chassis of the amp?
The reason I am asking is that the there is a whole chunk of the circuit that is grounded via pin 19. A high restance could help explain the correct emitter voltage and high collector voltages on T4 and explain the funny resistance measurements, If your probes were always connected to the board I am talking rubbish. Al
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4th Oct 2010, 12:00 pm | #89 |
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Re: Leak Delta 30 Amplifier - One Channel Down
If I'd known you had to get components from the UK I'd have happily have sent you a few resistors FOC. It's not as if I'm short of them.
It would be unusual for wirewound resistors to go high in value. They generally go open circuit due to a break in the wire, or low resistance due to adjacent turns touching. So long as they don't look discoloured I'd assume they're OK. I'd put the circuit back together around T4 and T5 and check the voltages there again.
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4th Oct 2010, 12:01 pm | #90 | |
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 12:06 pm | #91 | |
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Re: Leak Delta 30 Amplifier - One Channel Down
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If they get it out today I might even get them by the end of the week. It usually takes 4 to 6 days for things to get here. |
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4th Oct 2010, 12:06 pm | #92 |
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Re: Leak Delta 30 Amplifier - One Channel Down
As a double check have a look at the diagram there are a number of edge connector fingers all attached to the thick black line (ground) it is also connected to the chassis. With one probe touching the chassis you shoud see an ohm or 2 on each if these ground pins. Meter polarity should not matter here.
These connections may also be intermittent. Al
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I won't tell you how I discovered that. Last edited by Alistair D; 4th Oct 2010 at 12:08 pm. Reason: Added last sentence |
4th Oct 2010, 12:10 pm | #93 |
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 12:17 pm | #94 | |
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 12:25 pm | #95 | ||
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Re: Leak Delta 30 Amplifier - One Channel Down
Quote:
One probe on the chassis and the other probe to fingers 2, 8 and 19 (4 is not a ground) on the the board you have been working on. You are checking that there is a connection through the finger to the chassis of the amp.
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4th Oct 2010, 12:27 pm | #96 | |||
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 12:36 pm | #97 |
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Re: Leak Delta 30 Amplifier - One Channel Down
I am still not clear enough in my descrription. (it al seems very clear to me but then I have been doing this kind of work 30 odd years).
On the diagram you will see that one side of R32 is connected to finger 19. Connect one probe of your meter to this point on the resistor when the board is in place. The other probe to the chassis. the resistance should be 1 ohm or less. Please dont be afraid to keep asking until you are clear about what I am asking. Al
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4th Oct 2010, 12:45 pm | #98 | |
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Re: Leak Delta 30 Amplifier - One Channel Down
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4th Oct 2010, 1:10 pm | #99 | |||
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4th Oct 2010, 1:17 pm | #100 |
Nonode
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Re: Leak Delta 30 Amplifier - One Channel Down
You are correct I am misreading the letter B for 8.
At least we have ruled out another possibility. As Station X says go ahead and try it out. Al
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