Відео

induction coil?

I called marshall direct about 9 years ago and said i was a repair store.

@@subversivecraft thanks I can’t get Marshall any more and I got this old amp I’m trying to save. 🤷‍♂️

@@michaelcorrick8977 In the video I just cut the legs off the transistors and replace them on the board. Do you have the boards? You could mail them to me and I'll swap them over for you.

What you’re looking for is called a string hook. They’re available. Email kahler direct. Super glue will not hold.

@@subversivecraft Thanks. ...I doubt if I could install them myself ...Somebody in a local machine shop possibly ? ...Because this Kahler system was installed back in 1986 I was afraid that spare parts might not be available for it any more. The Kahler system was called 'The Professional choice' system , if that identifies which specific model it is. ?

​@@walterevans2118 I don't know of a model being called that. Chances are it's a 2300. You can take the entire tremolo apart if it's an actual Kahler. Take the trem off the guitar body. Then release tension on the load lever and remove the spring screws. Then remove the cam by loosening the pivot screws. Once the cams out you punch the hook pin out and it will slide out. You can then put the new hook in. It's pretty easy once you look at it. You don't have to do all the steps in this video but this is how you get to the hooks: ua-cam.com/video/-iGZg8Np8Bk/v-deo.html Good luck!

I have had it about ten years and is a first generation. It was a nightmare getting it fully functional but it works now. There are some updates you have to do to the circuit and replace a few capacitors with higher voltage ratings to get the bias stable. There is an italian language service document floating the web. If you can't find it I can email it to you.

I just got this one last week and it was damaged in shipping or the seller wasn’t completely up front as to its condition upon me purchasing it. When I opened it open it shows a date code of 10-93 I believe. Ampeg’s web site looks to only have bits and pieces of the schematics and documentation. The VL series is definitely overlooked and highly underrated.

@@marvinwarth8151 They're great amps but they're made by St. Louis Music (Crate) so some corners were cut. Awesome when running, but I can't say mine have been reliable. If you shoot me your email I can send you what tech info I have on the 503. I ended up making a footswitch out of a JCM 2000 TSL footswitch for the 503. I made these videos as a portfolio of work I've done and also to show a higher definition version of what Lee Jacksons video was. He has since pulled it and some parts were a little un-clear regarding wires because the one he worked on in the video was partially modded from stock.

They were cheap and plentiful once upon a time. Also they were very popular so to set yourself apart making it look cool was a thing. It always ended up looking worse imo. I used a rivet gun and put them back same as stock. Later 6505's use screws in this location. Good luck and don't forget to include the tube retainer when you re-rivet.

It doesn't work on this transmission but it is T10382

Roger. I went ahead and tightened up all of the screws that secure the sockets to ground. A few were definitely loose. I have an original 503 and had to add those wires in as per the "service bulletin" translated from Italian into english. It makes an appearance at the end.

I've had issues in my 503 when using unmatched tubes. If you set grid voltage apart it will be messed up when turning on attenuator as it's just variable resistor between grids. More dangerous is setting bias with attenuator on. Pots are interacting with each other. When I've turned attenuator off one tube went to 60 mA. I'm thinking about adding capacitor to prevent that bias shift@@subversivecraft

There is actually a service bulletin on the 503 to fix the bias issues. It involves changing the voltage spec of a few main caps, swapping a few resistors, changing the value of the slope pot, and removing a resistor in the slope circuit. It's also important to isolate the metal bar that is screwed to the chassis and touches the back of the bias pots. I covered mine in tape to keep it off the pots. If you want I can send, it's in italian though so I had to use google translate.@@KamilT138

thanks, I have that document@@subversivecraft

Well then to you I say rock on.@@KamilT138

Tweet tweet. I had the garage door open.

@@subversivecraft it was good reminds me of waking up

You're welcome. Yes there is a spot without a trace for one wire. That's how you can tell what goes where when running the wires. The traces are very brittle and can lift very easily putting it back together. If they lift you can just run the wires to the next component. Lee's video was helpful but the quality was pre HD and not very clear. I ripped it from YT years ago. The wires for the heaters/lights get swapped as I show from their factory locations. I would also recommend swapping those 1k 5w resistors and the impedance switch. If you have any other questions please ask. I hope the repair goes well!

Special tool is too thick to fit in between that curved fin portion of driver side transmission case and axle tulip itself. I had the VW manual for the procedure, got the correct model numbers for the tool and still no dice. It went back. It is a slide hammer tool. I worked on this for a week. I had to replace the front struts as well so they were out at the time. I even had a bit more room to work is what I'm getting at. I used the axle fork on the passenger side no problem from the bottom. The issue on the driver side again is that round fin. The only access is from the right which is blocked by subframe, control arm, and wheel well/frame. I cut the axle boot because mine was destroyed already and I was willing to try anything. I tried drilling a hole through both sides of tulip and attaching bolt to a chain slide hammering. No dice. It wasn't until I ground this down into a horse shoe that I was able to fit it in. I would work it, test, and repeat until it fit. Water was important to keep it as cool as possible to retain the integrity of the hardened steel. Once I had this behind the tulip it came out in 2 pulls of the slide hammer. I got the Axle popper set on ebay. Again though, it will not work on driver side. It's too big to get in there. AXLE TOOL: www.ebay.com/itm/352868452738?hash=item5228994982:g:f1MAAOSwt~hldzQo&amdata=enc%3AAQAIAAAA4CySq668HXptdtUidZwz7QEsl7KTF%2Bq4%2FmqOwtqD3erb7SAplU39U%2FzuAYYGqXztfLySoEKMkYbgYsVOkY3XcLGspfGvGrzggL1QN08bWYoRtknhXzLi%2B4VbNPH%2Bd5%2BjowkbbtWy9wjF90OshHZox0BM6iSqv6Subg1OBKahSJVg6pdYkAZXi%2BnL7Kc4CruiKg1wa4nKn9g29se7h6opXyoNl%2BgiyeLk%2BTPhXdUy8kHH5jfWkL7bpCIzmYSFKcfN%2BbNN9KjukdA%2Fuvk46VjvnaVSUCb7Sbgt%2FuR7D1N737UX%7Ctkp%3ABFBMpJvNmKVj

Ive seen the stable bias mods fail. The whole board becomes a ground plane and everything unites in a fireworks display. Doesn’t really matter where the bias circuits located if all other circuits become one. Your mileage may vary but not changing that board out is a bad idea. The modded boards sometimes take out the transformers when they go too. This amp for instance ate its power and output trannies. Rev 20 is the way to go or else you are literally playing with fire. If you like watching the process Ive done this 3 other times to my other 2000s check my other vids.

For me 50w aint cut it. The issue is also with the 50 watt models too. This is the board for those. britishaudio.com/products/marshall-jcm2000-dsl50-power-amp-pcb-mar-m-dl50-60-02-00

Yes the chip can ground out on the heatsink. Theres a mica insulator and insulated hardware to keep this from happening.

@@subversivecraft Thank YOU!!!

You bet. If you plug a speaker cable in while the amp is on it will blow the chips up.@@outerbanks854

Yes I just didn't film it. I like opening these amps and seeing what BS someone thought would fly.

In my experience the transistors are not really meant to push distorted audio and can fail. There is alot of information about this already but I wanted to make a video to help anyone who owns one. If I hadn’t of gotten it for free I wouldn’t own one however. I got this one for free because someone plugged the speakers in after turning the head on. The combos are not usually damaged this particular way because the speaker is always plugged in.

Link in the description

Thank you!

Win 7 here too.

@@subversivecraft 😂 Ok, same, same

I have one. Can't get it to work on W10, so yeh, I use an old laptop. It's a fantastic unit that can occasionally be found for a great price on eBay. Great studio addition. Worth a mobile rack unit for live gigs too.

Go for it!

Get the replacement board and you should be good.

You got this go for it. The USB port should be easier than a knob. Good luck!

If it sees a shorted speaker or has a speaker load connected while powered on, it will eat the transistors. I put some Noctua in a BV300h. Do you have the compatible model number for this amp?

Hope you're well and free.

@@subversivecraft I’m all good now. Thanks brother.

Do u guys have any upcoming tours or shows?

I have a 503 and 1002. 503 has been a nightmare. 1002 has had multiple faults. I did the wiring mod. 50 watt models aren’t as prone with half the draw. I have had to replace screens, reverb cables, LDR’s, tubes. Right now I’m bypassing the impedance switch and seeing if it behaves. At wits end with it. Sounds great when it works.

The answer is both.

Thanks man. I'm bruised from the abuse this and that ampeg have dished out on me. Amps been killer so far. Might buy it off my buddy. Fingers crossed.

@@subversivecraft did you watch my JVM video? I worked on that amp several times before finally isolating those pins. It was definitely a last resort.... The customer is still rocking it though, so I think you are good.

@@jloewenheim I did see your video! I wasn't aware the JVM's had an issue too. Good to know, will pass on them. The original 2k board was modded to have the pins isolated and some traces cut to help prevent the issue. It didn't work because the board was conductive and incurred resistance with heat. Junk. Mod was expensive when it was done.

@@subversivecraft Again, hopefully, it sticks. The diameter FR4 used on these was a bad choice by Marshall in all of those amps. IMHO, the best option is to pull the boards, keep the transformers, and then insert a turret board and wire up as a hot-rodded Plexi or JCM 800.

Fact. Can confirm amp sounds amazing after board swap. No more power tubes red plating.

@@subversivecraft now it's repaired it will be a decent workhorse 👍