NAD - Vantage t50r amp

Ankhanu · Post by **Ankhanu** » Sun Apr 22, 2012 4:20 pm

My friend has had a Vantage T50R amp for several years, but it hasn't been working for a long time. He was going to get rid of it, so I said I'd take it off his hands. It's a 112 (8Ω) dual channel tube combo, with 4x EL84s and 3x 12AX7s and reverb. From what I gather, it's the same amp as the Seymour Duncan 84-40 (Owner's Manual PDF), rebranded for Vantage, making it a 40W, with a tone (apparently) somewhere between Fender and Vox.

I plugged the amp in and hooked up a guitar, and could just barely hear some sound coming through the speaker amid lots of hum and some crackle. I jiggled the cord in the input, getting nothing different, and tapping the housing just resulted in some reverb ping and more hum. I took a look around back to check the tubes; the power tube on the far left was lit up quite bright, the middle two not so much, and the far right looked pretty much dead. I swapped the two on the ends, and the tubes lit up as before, suggesting the issue is the tubes themselves and not the circuit/sockets. I plan to pick up a matched quad set and see if I can get the amp running again (EDIT - Make that ordered an new set for the ceaps on eBay). The preamp tubes looked to be fine.

Anyone have any experience with either of these amps?? Have any information that contradicts what I found? Info on the Vantage (and the SD) appears to be fairly sparse.

I'll get my wife to take some pics later this eve and post them; I work out of town through the week, so am nowhere near it until Thursday night.

Kelyndra · Post by **Kelyndra** » Sun Apr 22, 2012 10:06 pm

spirograph · Post by **spirograph** » Sun Apr 22, 2012 11:24 pm

(deleted)

Ankhanu · Post by **Ankhanu** » Sat May 05, 2012 4:06 pm

I replaced the EL84s, the new ones all light up pretty evenly, and I had to replace one of the 12AX7s with one I'd pulled from my Twin a while back... still no sound signal. I can still get reverb through the speaker if I tap the chassis, and the speaker works as an extension for other amps, so the driver is also good. Guess I'll have to take the amp out of the chassis and take a look at the circuit.

Ankhanu · Post by **Ankhanu** » Fri May 25, 2012 4:46 pm

I finally had the energy/time to pull the amp out of the cabinet and take a look at the components... got definite confirmation on the Seymour Duncan connection, it's built with a Seymour Duncan 412480 Rev. A circuit:

I gave the board a once over visual inspection, but don't see anything obviously untoward. All the capacitors are still sealed, there are no burned resistors, the solder points seem to be solid, etc., but I haven't hit it with the multimeter yet, and I hesitate to do so, since I'm completely inexperienced.
I did contact Seymour Duncan and they sent me schematics for the transformer connection for the Rev. B of the circuit, and a schematic for the Rev. C board... hopefully they're not too different from the Rev. A in my amp. If nothing else, they should help the technician I bring it to, if I bring it to someone.

Now for a photobomb of the internals of the amp!