Amazing what's out there on CL!

[olddawg]

Honestly guys... I'm pretty sure this is exactly what VHT is selling as their Standard 18. I looked at some google pictures and it matches their owner's manual exactly. I'll see if I can convert my iPad pictures into some jpegs I can post. I got to the game late. At $60 apiece I would have bought ten of them and shipped them to people on this board for cost if it wasn't the last one. I'll be on it if he gets more. If anyone has access to VHT schematics, a copy would be appreciated, but it's pretty much a bare bones two channel TMB 18 watt variant. Now I'm looking for a dead SS amp cabinet locally to mount it in. Quick, cheap, and functional!

[DrGonz78]

I bought two of those 18 watt VHT's off of Ebay over this past summer, dirt cheap. Mine included chassis, pots & tube sockets pre-wired, PT, OT and the VHT cabinets. Actually for Chinese stuff it is rather good quality. The seller was out of San Diego area and since Olddawg is in Carlsbad I knew right away after reading his first post these are similar. I had posted a thread a while back trying to figure out how to wire the primary section for the PT's. Difference here is that it was obvious that it had universal power transformers installed. One cab head had the VHT name plate and the other one it was missing. There was another listing on Ebay around the same time to buy circuit board, but I wanted to do that part myself. I also bought about 6 EL84 tubes from them too for about $2-3 a tube. A while back I had built a one channel 18 watter amp called the Scurvy Shyster Bastard with help from the forum here. My idea now is to put that channel into this thing for the lead channel and then design a nice simple clean channel. I am starting that project very soon and will finally get into relay's or optos for channel switching.

BTW it sounded like someone was building these (or assembling them) as their own business. At some point that idea failed and now there were multiple people selling these things off in the San Diego area.

[olddawg]

I bought two of those 18 watt VHT's off of Ebay over this past summer, dirt cheap. Mine included chassis, pots & tube sockets pre-wired, PT, OT and the VHT cabinets. Actually for Chinese stuff it is rather good quality. The seller was out of San Diego area and since Olddawg is in Carlsbad I knew right away after reading his first post these are similar. I had posted a thread a while back trying to figure out how to wire the primary section for the PT's. Difference here is that it was obvious that it had universal power transformers installed. One cab head had the VHT name plate and the other one it was missing. There was another listing on Ebay around the same time to buy circuit board, but I wanted to do that part myself. I also bought about 6 EL84 tubes from them too for about $2-3 a tube. A while back I had built a one channel 18 watter amp called the Scurvy Shyster Bastard with help from the forum here. My idea now is to put that channel into this thing for the lead channel and then design a nice simple clean channel. I am starting that project very soon and will finally get into relay's or optos for channel switching.

BTW it sounded like someone was building these (or assembling them) as their own business. At some point that idea failed and now there were multiple people selling these things off in the San Diego area.

Yep... the plot thickens! Probably the same guy. The place is a hole in the wall called "James Hood Guitar". http://www.jameshoodguitar.com/ Used to be the old "Buffalo Bros". Just a hole in the wall now. He told me to get back in touch with me if I needed more parts. Lol. I picked up an incomplete 36 watt Chassis too as I said before. Still odd that the 18 watters had an Australian PT and power cord.

[DrGonz78]

Yup that's the guy I bought mine from too.

[olddawg]

So... I pulled the bells off of the Australian PT. There were no internal 120 vac primary taps although it is well made. It's a bit of a paperweight in the USA, lol... No worries. I'll just swap the PT out of the 36 watt chassis for the moment. It looked like they used the same PT on both amps anyway. It looks exactly the same except for the primary. The only major difference between the 2 amps is one chassis has 2 more EL84s. The front panel is exactly the same too.

[olddawg]

Date codes and writing on the chassis make them appear to be from 2009.

[Mick Bailey]

230v covers most of Europe, too. Even the UK. Rather annoying as we're on 240v and the tolerance of the specification is supposed to include us. Means most amps run over-voltage and motor-driven stuff suffers additional heat losses.

[Chuck H]

Even here on the other side of the pond we deal with it. I happen to like some of the shelf offerings from Hammond. New trannies have a 125V primary (we actually have 120V most of the time, sometimes the wall VAC goes up to 127 though) but older Hammond stuff (which is mostly what I've used) has a 115V primary. So we have sort of the same thing. Run a 115V primary on 127V for a 4.7:1 step up transformer and a 270-0-270 PT is now a 300-0-300 PT!!! NBD for some applications, but with tubes like el84's where you need to be vigilant about Vp... I do have a stock of small value, high wattage resistors for taming filament circuits too.

[DrGonz78]

I do have a stock of small value, high wattage resistors for taming filament circuits too.

In those cases you might pop in a pair of 8BQ5's if the filament voltage is a bit high. I got some NOS one's that I am waiting to try out but waiting for the right opportunity.

[Chuck H]

In those cases you might pop in a pair of 8BQ5's if the filament voltage is a bit high. I got some NOS one's that I am waiting to try out but waiting for the right opportunity.

Those could end up real handy if you bag an old amp or tranny with a 110V primary and you're in an area that's typically at 125V (and often 127V) from the wall. If the filament wind was under loaded just a little you could get something like 7.6V on the heaters. That's within 5%

[Tom Phillips]

...If the filament wind was under loaded just a little you could get something like 7.6V on the heaters. That's within 5%

Chuck,
Did you mean to write 6.6V ?

[Chuck H]

Nope. That quote is isolated from it's context. If you put 127VAC into a 110V primary AND the filament wind is under it's designed operating current...

110/17.5=6.28
127/17.5=7.25

Now add a little for under current and Bob's your uncle

I don't think it's uncommon for filaments to be .3 high from lower than expected operating current.

[g1]

The context being with reference to using tubes with 8V heaters? (8BQ5's)

[Chuck H]

That too? I didn't think that got lost. I thought the potential for 7.6V was in doubt. The quote, taken by itself, could seem to imply that I indicated 7.6V was possible with only an under current condition. That's not the case.

[olddawg]

Finally got some pictures to upload. Funny works from my iPad but not my iPhone. Anyway I completed this amp with the parts off of CL I described earlier. I ended up replacing the Australian PT in the 20 watt amp with the American PT off of the 30 watt chassis. The amp doesn't seem to mind and the PT is just slightly taller. When I build the 30 watt version I'll probably find a 20 watt PT and swap it back out. Now to build a cab. I've been looking for a dead doner combo but no luck so far. I I have some clean 1x12 planks which will probably be fine. Anyway here's the pictures for those who were wondering if it was really a VHT product. Sure seems to be to me. Sounds pretty good. Plenty loud to club with.