Vintage Ampeg SVT Voltage Help! Australia

Lenorr · #1 12-17-2012, 08:01 PM

Ok so currently I am in Australia and have a 2012 ampeg 810av cabinet. I want to run a vintage head with it. I have one that I can buy from the US. My only question is, what kind of power converter will I need. The SVT head is 300w so will that require 300 watts just to run it?. I've read that Australian power sockets run between 220-240 volts, while Americans run at 110-120. Also being a vintage head will it have any troubles running a modern cabinet?. Any help regarding converting voltage would be greatly appreciated. This is must first time dealing with this sort of thing.

B-string · #2 12-17-2012, 08:10 PM

As far as running a modern speaker cab no problem at all. As far as the voltage question many models had a universal transformer that can be rewired for 220/230. Would need to know what model/year made.
For a step-down transformer you would need one rated minimum of 900 watts (min. 2X the rms plus extra due to amp inefficiencies).

Lenorr · #3 12-17-2012, 08:28 PM

Ah ok, so would you need to rewire for 220/230 or could you just run it straight through a step down transformer. I'll found out what year the amp is aswell.
So something like this http://performanceshop.com.au/1000W-...8Zed_3161.html

JOE EDO · #4 12-17-2012, 08:35 PM

B is all over it. There would be taps/wiring on the power transformer for 220/230. If you have the year, check the net for a schematic and that will hold the key as to what gets connected/ unconnected.

Lenorr · #5 12-17-2012, 08:37 PM

Ok well I've discovered that it was made in 1979. I'll have a look for that schematic. Ok just so I understand. If it was to be rewired to 220/230. You are saying that there would be no need for a step down transformer. It would be able to run straight into an australia power socket

B-string · #6 12-17-2012, 08:40 PM

You can run through a step-down transformer, they are heavy themselves. Would be better if the amp would support rewire to 220/230.

Lenorr · #7 12-17-2012, 08:52 PM

Ok good to know, thank you so much for all your help. I know a guy who specializes in amps and musical gear so I'm sure he will be able to help me rewire it.

JimmyM · #8 12-17-2012, 09:35 PM

I am 90% sure old SVT's have to have a new power tranny installed to do 220/240. The good news is that they're easy to find and won't change the sound of the amp. The bad news is they're $255 at www.fliptops.net and still have to be installed.

You could use a step down transformer, but if I'm lugging an SVT, I wouldn't also want to lug around something the size of a car battery that weighs as much as an SVT, too

BTW, don't take my word for the PT, but hopefully someone who knows definitively will chime in soon.

B-string · #9 12-17-2012, 09:40 PM

The filament trans also but I believe some MTI's had universal. At least the fading memory thinks so? The money spent if not, is well worth it IMHO . Better spent than lugging a step-down trans around.

Lenorr · #10 12-17-2012, 09:58 PM

Ok thanks, I'll keep that in mind when I take it to the tech.

beans-on-toast · #11 12-17-2012, 09:59 PM

If you edit your original post and select advanced, you can modify your title. Add Australia in there, you are bound to get someone from there that can tell you what they use with US amps.

Aussie Mark comes to mind. You can send him a private message (top right corner of your screen).

In general, you get what you pay for. If you get a power converter, go for quality.

Lenorr · #12 12-17-2012, 10:02 PM

Ok thanks for that. Yeah I'm not going to cheap out on this haha.

Downunderwonder · #13 12-17-2012, 10:08 PM

Definitely some SVT's have had a simple rewire to work on 240v.

RobbieNuke · #14 12-29-2012, 02:57 PM

The power transformer (PT) in original SVT's made in USA by Ampeg from 69'-79' are easily rewired for export voltage (220-240 VAC). The wattage will still be the same. I'm 99% sure MTI units (made in Japan) are the same way. You will only have to change the plug on the power cord.

But instead of cutting off the original plug, replace the entire power cord with a new one that has the correct plug molded on already. You will be in there changing the PT wiring anyway, so do both things at once.

B-string · #15 12-29-2012, 03:05 PM

You are aware that '69-'79 includes three different owners of the Ampeg brand. Ampeg stopped being a company of their own when to sold to Magnavox.

RobbieNuke · #16 12-29-2012, 03:59 PM

Yes... I'm aware of that as are most Ampeg aficionado's. That's why I made the point of saying all USA made SVT's... pre- and post-Magnavox. Actually, Ampeg was bought out by Unimusic in 1967 so Ampeg was under control/direction from an outside source at that point... years before Magnavox/Selmer took over.

Getting back to schematics, there doesn't seem to be any MTI era schematics available... except maybe in Japan.

Jerrold Tiers · #17 12-29-2012, 04:03 PM

I have rarely seen an old (as in vintage) US-made SVT which was re-wirable...... They DID exist, but it seems that most were made for US and then it didn't matter.

The MTI units might have been different.... being made in Japan, I'd actually be surprised if they were not re-wireable, but MTI might have had some or most made as 120V only.

I don't know what the cost of a step-down transformer is over there, it might be competitive with a new power transformer set (High voltage and filament), or might be much cheaper... in case the unit is NOT rewireable.

mr.mow · #18 12-29-2012, 04:28 PM

I went through a similar thing, modern SVT can be retapped to 240v, but it's not a 5 min job and a few bits and pieces need to be replaced, I was told about $300.

Old ones.. Good luck.. Can be done but will be expensive.

As for shipping an SVT from overseas.. Be aware they are very very heavy and quite fragile.

This is how mine arrived.. They don't ship well, there was nothing to salvage here.

If you are keen on a US made SVT, check out the oz bass forum, there is a US made modern one for sale and last time I looked a magnavox era one for under $2000

B-string · #19 12-29-2012, 05:07 PM

I think I just had my eyes water up! People just have no clue how to PROPERLY prepare for shipment!

mr.mow · #20 12-29-2012, 05:14 PM

Quote:

Originally Posted by B-string

I think I just had my eyes water up! People just have no clue how to PROPERLY prepare for shipment!

Both of the transformers had punched through the main boards then bounced around destroying everything in there!

Good packaging wouldn't have saved it, it had been dropped good and hard, by the looks of it from a good height.