Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
1969 Ampeg SVT
- Thread starter K-Funk
- Start date
thanks i will look for the dates in the next few days.. where is this tube relay people speak of?
Looking at the back of the amp its far left side, next to the multi connector block. There's also a picture of one on the previous page.
Invalid Link Removed
the empty socket right behind the transformer is where the tube relay goes. most of them have been defeated with a shorting plug, though. turns out if the relay goes bad, the whole amp shuts down. i bought one for mine and the tech refused to install it. after he told me that, i went with it.
btw, that rogue 6550 has been fixed since then...all 6146's now
the empty socket right behind the transformer is where the tube relay goes. most of them have been defeated with a shorting plug, though. turns out if the relay goes bad, the whole amp shuts down. i bought one for mine and the tech refused to install it. after he told me that, i went with it.
btw, that rogue 6550 has been fixed since then...all 6146's now
- Feb 16, 2008
- 21,240
- 23,633
- Disclosures
- John K Custom Basses
Anything i should have serviced right off on this beast? It works and sounds great. It appears to have original tubes except for one. Sounds like it should... some static in the plastic rockers but otherwise fine. Has an upgraded three prong cord and appears to have a replacement power switch. I am assuming that tube relay is bypassed (or whatever they do to get around it) since it currently has no tube in the socket. Anything i should look for as a red flag and have serviced? Also, are the early blue lines worth more then later SVT's? Strangely this is my first Ampeg. I've used an old Musicman hd-130 as a bass amp for the past ten years. Man what a difference! (not all bad for bass though!)
if it ain't broke, don't fix it. when it breaks, worry about it then. maybe you could spray the rocker switches with deoxit, and that's all i'd do for now.
The time delay relay delayed the High Voltage turn on time 60 seconds to allow the power tubes to stabilize. The original might have been 90 seconds, but they only make a few these days and 60 is most common.
It's not really necessary, but was sort of classy and kept the amp from making funky ishy noises as you played and it warmed up.
It's about as useful as the interlock that wouldn't allow the amp to have high voltage without the speaker connected. A real PITA, but I bet it kept a lot of guys from melting amps in those early days.
The relay was made by AMPERITE and the model number is 115NO60. Basically 115V heater, a normally open contact and 60 second delay. The price for "1 each" is $152 and change, plus dealer prep, tax & license and delivery from Newark Electronics.
I have one new in the box somewhere in my 30 electronics parts bins. As in those 40 quart Rubbermaid giant tupperware boxes.
I bought it new for peanuts compared to today. At $152 bucks it's priceless.
But if a guy really wanted to restore an amp, you have to have it. They last almost forever, but when they fail, you better have a "Jimmy Plug" to jimmy the bitch.
BOB
It's not really necessary, but was sort of classy and kept the amp from making funky ishy noises as you played and it warmed up.
It's about as useful as the interlock that wouldn't allow the amp to have high voltage without the speaker connected. A real PITA, but I bet it kept a lot of guys from melting amps in those early days.
The relay was made by AMPERITE and the model number is 115NO60. Basically 115V heater, a normally open contact and 60 second delay. The price for "1 each" is $152 and change, plus dealer prep, tax & license and delivery from Newark Electronics.
I have one new in the box somewhere in my 30 electronics parts bins. As in those 40 quart Rubbermaid giant tupperware boxes.
I bought it new for peanuts compared to today. At $152 bucks it's priceless.
But if a guy really wanted to restore an amp, you have to have it. They last almost forever, but when they fail, you better have a "Jimmy Plug" to jimmy the bitch.
BOB
i bought a 115no30 at my local nos tube store for $25. amperite, too. saw the $150 prices when i was shopping for one, though. i should sell it for $75
Nice one, now check the back of one of the balance pot's it should read 137-xxxx.
A note of interest. According to an RCA 6146A tube data sheet, they recommend that the minimal warm up time -- that is, the amp in standby with the heater voltage applied -- is 60 seconds. That is why they used the 60 second relay (Amperite 115NO60) that Bob mentioned.
Also, if the tube is going to be in standby for between 15 minutes and 2 hours, the heater voltage should be reduced to 80% of normal. This is not possible to do with the SVT. Beyond 2 hours, power should be shut off.
Of course none of this really matters as it is for optimal operation. For longer tube life, let your SVT's warm up for at least 60 seconds and don't let them sit in standby for extended periods.
Also, if the tube is going to be in standby for between 15 minutes and 2 hours, the heater voltage should be reduced to 80% of normal. This is not possible to do with the SVT. Beyond 2 hours, power should be shut off.
Of course none of this really matters as it is for optimal operation. For longer tube life, let your SVT's warm up for at least 60 seconds and don't let them sit in standby for extended periods.
