Parcel breakages and TVM Sound PK200 KT88 amp

Been having a bad time with amps being delivered. First this SC120 my mate rebuilt for be had the case broken and chassis bent with a dropping:

Bit of a pain but I have other sleeves to use while I glue it up. Transformers work fine when wonky.

But this one will be a bit harder to sort:

It is a TVM Sound TK200, some sort of PA I’ve not every heard of aside from seeing another on ebay.. Case has a big space in the bottom for unknown purpose, so was probably gonna cut it down anywa,y but whole new one is on the cards now.

Now for the important bit, guts:

Looks like a SS preamp on each input. Two KT88s powering it. Previous owner had it in storage, and fired it up to test it, pretty bad move, lots of smoke ensued.

As expected, old dried up cap let go when suddenly presented with full voltage, these need reforming by starting with low voltage or replacing. Here’s the rest of the insides, pretty simple as is just power section:

And the exciting part:

Woo, Gold Lion KT88, hope they still work.

Inside a Blackstar HT valve distortion pedal

I quite like these pedals, they respond to valve changes, which tells me the valve is actually doing the appropriate work. Got this one with a bust switch. Phoned up Blackstar, and aside from telling me there are no user serviceable parts (ha) they sold me a new switch for it for a sensible price (unlike Ampeg who stiff you).

Not horrific to get into, two layers of circuit board, 4 screws holding them and the bottom, plus removing the jacks an the switch nuts. Just gotta wait for the switch to arrive an solder it in, should be good to go.

Sound City 200 guts

Opened it up.

Serious iron.

Some work done in here.

They even left notes, and a new switch in a bad, not fitted, not sure why.

Bunch of parts on order for this, put away till they arrive.

Sound City 200

Arrived today:

Back, with those all important trannies:

Gonna be cleaning and restoring this as main priority that doesn’t pay.

Shipping casualty

A mate of mine rebuilt one of the Sound Citys for me, shipped it back. Didn’t arrive too well:

Been dropped for a fair height, that is screwed and glued.

Cropped my feet out of this one, check that tranny:

Rivnut torn out, and bit of a bend in the chassis:

I’ve swapped the chassis into another sleeve and squashed in the rivnut, replaced the bent screws and it fires up fine. Tranny is stuck with being wonky though. £600 valve or £525 unvalved if anyone wants it. No hurry to sell cause this will be my main amp for the moment.

Sansui Stereo reciever Six hi-fi amp

Opened up my stereo for a clean and try and sort a dicky input.

Lots going on in here.

Not less on the other side.

Some bits are pretty Star Trek.

Other bits are works of art.

Looks like the problem might be my phono lead.

 

Just jammed a bunch of stuff on ebay

http://www.ebay.co.uk/sch/incarante/m.html?item=300646598150&sspagename=STRK%3AMESELX%3AIT&_trksid=p3984.m1555.l2649&_trksid=p4340.l2562

Can do deals not via ebay if you are interested, I start stuff at the sort of money I want to get +fees. Go direct and you can save the fees.

Assembling the dummy load

Dad posted me the thermal goo I left at his workshop so I can actually put this together now.

The goo, I used the top stuff for PC processor heatsinks, total overkill, but means the leftover is useful for a PC that I kind of want assemble at some point. Here is the kit:

The bottom contact area of the resistors was actually pretty far from flat, so I used wet and dry paper and the flat surface of the heatsink to grind them a bit flatter, mostly the burr round the holes, not super ideal, could have done it for a lot longer for flatter, but it gets to a point of diminishing returns:

Turns out the thermal good looks exactly like the ground up metal I just spend a bunch of time cleaning off the resistors, if I’d used silicone oil instead of water while doing it, it would probably do the job. It also photographs weirdly:

Great effort to spread it really thin, looks like I put loads on there.

Screwed down tight, had a wiring rethink for a better way of doing it, after I started.

The cunning plan was to clamp the wires down using the existing screw holes. Finding a suitable clamping item was the challenge. Remembered my meccano that I brought back from parents after Christmas. Too precious about it to use not already broken parts. Problem with the broken its is they were already fatigued. Hence pile of rejected bits, and ‘good enough’ broken bit eventually screwed in place.

Gone for two 200w 4 ohm loads, so can use both in series or parallel for 2 or 16 using an adapter, or just use one. Since I have no scope or distortion meter, not likely to be pushing max RMS from amps, its mostly for a quiet load when I’m doing live tinkering and biasing and such.

Done. Now watch it be ages till I have a use for it.

Peavey Triumph 60

Three channel 1×12 combo, might be Peavey’s thing to be bit too ambitious, one of the channels sounds totally rubbish. Came to me to see if I can figure why. According to the internet snipping one of the jumper wires in the pre sorts out a bad sound in the gain channel. Opened up to have a look and someone had been in there before and there was a cap bridging two jumpers. Without yoinking out the board, not gonna figure what it id, but first thing was lift it off and see what difference it made. Turns out not as much as putting decent valves in the preamp. Tried the clipping the wire mod too, still doesn’t sound great.

Portaflex impression. Not much interesting here.

Insides, tops of caps look bit round, push them and they feel hollow underneath.

Another view, bulging caps at the top, lifted cap and snipped wire below. Not convinced it made loads of odds comapred with better valves.

Other thing I’m doing, restring and setup on this cheap acoustic. Definitely something wrong with it:

On of the threads on the tuner screw in grommet things was miscut from new so doesn’t bite, peril of cheap guitars and a valid warranty return if anyone had noticed.

Carlsbro 50 Top

Back to amps. BIN Ebay snag, sometimes risk, but I can fix most stuff and I have the 60PA if desperate need for spares. As it turned out, aside from a duff valve and a fairly impressive collection of dead spiders (lots of variety) this one wasn’t far from basically working.

Too impatient to take it apart to photo it whole.

The top, brushed and hoovered but the original valves have grown a nice film. Partridge power tranny, but not output, would have preferred other way round. Minimalist two pre, two power valves.

Simple guts, most of the preamp stuff is actual point to point on the pots. No spewy caps. Problem I have now is the lack of a bias pot, currently the valves red plate so it needs bringing down, off to chambonino.com to see if there is a pic showing what resistor it is without having to pull the board. Note the board is wired to valves on both sides, so is a desoldering job just to look at it. That is the place where turrets are ahead of PCB, so if you aren’t of the inclination to be poking about inside, don’t worry about an amp being on PCB.

Also have got this pile or parts to ID/let me know if you want it:

Is power supply section from a stripped out organ.