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Mesjoggah
Gold Member
Netherlands
595 Posts |
 Posted - 04/02/2009 : 14:43:14
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Today i've got my Ph-1 which i bought broken on Ebay.
I knew it wouldn't work so i opened it and took some pictures of the inside and noticed some work was done earlier.
The LED and switch work (on both battery and adaptor) and in the distance there's kind of a click hearable. When i put a distortion before the ph-1 and crank my amp up i can hear distortion far away but when i press the switch the sound remains the same with no effect added.
Q1, Q2, Q3 and Q4 aren't the stock ones and might be a wrong replacement? |
Edited by - Mesjoggah on 04/02/2009 14:44:03 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/02/2009 : 16:01:59
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Hi Mesjoggah
There has been some extra-extra work carried out on this PH-1.
I don't doubt that it's fixable.
The FETS are substituted, & a lot of re-soldering on the rear of the PCB.
And not good substitutes, they look like BF245's
the 3403's look to have been replaced as well.
Not many people know, or actually care, but the FET's have to be matched, for the PH-1 & other similar designs, to swish/swoosh correctly & smoothly.
They use the FET as a sort of variable resistor.
Looks like the flip flop transistors have been either, re-soldered or swapped as well?
Can I ask how much you paid for it?
And is the case in good condition?
Yes I would have still bought it.
Older analog stuff is very repairable.
Perhaps Laurie will chime in here as well.
I believe he is more familiar with the PH-1 series, than I am.
Regards Dr. Bob 
5050 |
Edited by - Dr. Bob on 04/02/2009 16:02:45 |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 04/02/2009 : 16:27:07
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Hey Bob, i read the service notes and noticed the FET's had to match and like you said Bob these are BF245b's. The case is in very good cosmetic condition and this PH-1 came with original box and manual too, i paid 99 euro's shipping included which seems fair to me, i have been looking for a PH-1 for a while now and never found one cheaper than 95 euro- shipping not included and this one had the plus of having box and manual.
Anyway: i comleted my phaser collection!
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Edited by - Mesjoggah on 04/02/2009 16:29:03 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/02/2009 : 16:49:57
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Hi Mesjoggah
Very nice - well worth fixing, even if it costs you a few $$$ more.
Now - how are your soldering & electronics repair skills?
Regards Dr. Bob |
Edited by - Dr. Bob on 04/02/2009 16:50:41 |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 04/02/2009 : 17:57:44
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quote:
Originally posted by Dr. Bob
Hi Mesjoggah
Now - how are your soldering & electronics repair skills?
Regards Dr. Bob
Soldering isn't a problem, i just need a guide on what to check to locate the error. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/03/2009 : 13:18:32
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G'day Mesjoggah! You find them all, eh?
I'd be happy to give you a hand fixing this, but been REALLY busy in my real job lately - so might be a bit hit and miss about when I can actually help.
So, using the audio probe we used on the ODB-3, check that there is strong signal on pin 5 of IC2. Then:
- check what signal you get on pin 2 of IC2, with the LED on and off
- check what signal you get on pin 8 of IC2
- and then use the mulitmeter to check the DC voltage across C10
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 04/03/2009 : 18:55:42
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quote:
Originally posted by Laurie
G'day Mesjoggah! You find them all, eh?
I'd be happy to give you a hand fixing this, but been REALLY busy in my real job lately - so might be a bit hit and miss about when I can actually help.
So, using the audio probe we used on the ODB-3, check that there is strong signal on pin 5 of IC2. Then: OK
- check what signal you get on pin 2 of IC2, with the LED on and off No signal
- check what signal you get on pin 8 of IC2 No signal- and then use the mulitmeter to check the DC voltage across C10 5.40 volts
Thanks Laurie, i would not have bought it if i couldn't rely on guys like you!
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Edited by - Mesjoggah on 04/03/2009 19:51:15 |
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verivorax
Platinum Member
Canada
1185 Posts |
Posted - 04/03/2009 : 20:14:33
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Beautiful PH-1. Hope you get it back to life! What's the serial?
Having incredibly knowledgeable and helpful members/admins does make all of our purchasing a bit more worry-free, I think!  |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/03/2009 : 20:53:00
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quote:
Originally posted by Mesjoggah
quote:
Originally posted by Laurie
G'day Mesjoggah! You find them all, eh?
I'd be happy to give you a hand fixing this, but been REALLY busy in my real job lately - so might be a bit hit and miss about when I can actually help.
So, using the audio probe we used on the ODB-3, check that there is strong signal on pin 5 of IC2. Then: OK
- check what signal you get on pin 2 of IC2, with the LED on and off No signal
- check what signal you get on pin 8 of IC2 No signal- and then use the mulitmeter to check the DC voltage across C10 5.40 volts
Thanks Laurie, i would not have bought it if i couldn't rely on guys like you!
IC2 might be dead. Could you swap IC1 and IC2 and take the measurements again? |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 04/04/2009 : 08:56:41
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quote:
Originally posted by verivorax
Beautiful PH-1. Hope you get it back to life! What's the serial?
Having incredibly knowledgeable and helpful members/admins does make all of our purchasing a bit more worry-free, I think!
Yep! the serial is 9200 |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 04/04/2009 : 08:59:48
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quote:
Originally posted by Laurie
quote:
Originally posted by Mesjoggah
quote:
Originally posted by Laurie
G'day Mesjoggah! You find them all, eh?
I'd be happy to give you a hand fixing this, but been REALLY busy in my real job lately - so might be a bit hit and miss about when I can actually help.
So, using the audio probe we used on the ODB-3, check that there is strong signal on pin 5 of IC2. Then: OK
- check what signal you get on pin 2 of IC2, with the LED on and off No signal
- check what signal you get on pin 8 of IC2 No signal- and then use the mulitmeter to check the DC voltage across C10 5.40 volts
Thanks Laurie, i would not have bought it if i couldn't rely on guys like you!
IC2 might be dead. Could you swap IC1 and IC2 and take the measurements again?
Did a switch, now i have a good signal on pin 5, a weak, kind of distorted signal on pin 2 which gets more noisy when the LED is on and a weak signal on pin 8. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/04/2009 : 15:50:18
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OK... if it was mine, what I'd do next is I'd replace IC1 and IC2, and order some 2SK30's to bring Q1, Q2, Q3 and Q4 back to factory spec. While the BF245b's should theoretically work, 2SK30's are easy to get so I'd change them back.
Strictly, Q1,2,3,4 need to be matched. I'd probably order a bag of 20 and measure them to find 4 that match (it kind of doesnt matter what the absolute spec is, as long as they are matched - the VR1 trimmer lets you adjust the operating point of all four as a group).
3403 opamps aren't that easy to get, although these guys have them, and they are close to you: http://www.vintageplanet.nl/semiconductors.html
If I couldn't get 3403's I'd try TL074's (because I have them).
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Edited by - Laurie on 04/04/2009 16:34:25 |
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Dr. Bob
Moderator
Australia
6593 Posts |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 04/04/2009 : 19:22:52
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Ok, i'm gonna order two MC3403 op-amps from them but those 2sk30's i need, are they all the same?(apart from the matching) service notes says
2SK30ATM-Y FET
2SK30ATM-0 FET
2SK30ATM-GR selected for PH-l
How about -y, -o and GR? |
Edited by - Mesjoggah on 04/04/2009 19:26:08 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 04/04/2009 : 21:06:22
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| It's the "selected" that's important - selected means matched (and as noted in the serevice notes it applies to Q1 thru Q4). That article over at geofex explains it pretty well. If they arent matched, they won't phase. The trick is to buy enough of them so that you will find 4 matched in the batch. I'm guessing 20. |
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verivorax
Platinum Member
Canada
1185 Posts |
Posted - 04/06/2009 : 16:42:23
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| 9200.. I think this is the most commonly seen ink-stamp serial number.. These come up all the time! |
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Topic |
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PH-1 trouble
