Upgrade input transitor - may be repeted question [message #26178] |
Sat, 03 June 2017 19:46 ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
Saransk
Messages: 20 Registered: February 2017 Location: Northern Virginia
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Junior Member |
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A common thread is that Q1400/ Q1500 (the first input transistor on the 1400/1500 (SE4002)) is prone to "destruction" when overdriven.
Since the various vintage Kustom amplifiers were designed when the output of most guitar pickups was lower than the "hot" pickups which are now standard on most guitars, the first input transistor often is blown by pedal boards and high output pickups.
At the risk of asking a previously discussed question, is there a simple upgrade for the first input transistor that will handle the higher input voltages of today. Either a darlington configuration or just a "stronger" transistor for that first position that can handle a higher input.
While I could put a transistor socket in the first position to facilitate quick replacement, it might be nice to avoid the issue altogether.
Thanks
Michael
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Re: Upgrade input transitor - may be repeted question [message #26180 is a reply to message #26178] |
Mon, 05 June 2017 13:26 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
chicagobill
Messages: 2005 Registered: April 2003
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Senior Member |
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Agree with Steve about the input transistors being reasonably immune from damage. If they were that bad, there would be no working amps out there with original transistors.
Transistors can die from any number of things, the fact that some of them have given out, doesn't mean that they all should be replaced. It's like getting a flat tire and supposing that all 4 tires are defective because one went flat.
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Re: Upgrade input transitor - may be repeted question [message #26213 is a reply to message #26178] |
Mon, 26 June 2017 06:08 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) |
stevem
Messages: 4768 Registered: June 2004 Location: NY
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Senior Member |
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Its funny you mention the hammering effect , but you need to think about the era even the metal face amps where made in, as there where no overeound hot pickups back then unless you had them made for you.
The metal face amps that came about in 71 did as you posted have the two different inputs with one being 3 db down ( 1/2 volume ) from the other, but in general Kustom was getting complaints from six string player about needing more gain out of the 5066 preamp board ( the preamp without selectone )so the engineers issued a mod in Nov of 71 for the 72 production run of the 150 and 250 series amp that provided more gain.
They also sent out to all there dealers info on how to do this mod on the earlier amps should a customer want such.
The mod is a simple swap out of 3 resistors and 1 cap.
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