Ashdown Five-Fifteen 100w combo keeps blowing fuses. Help me?

[reddwarfer29]

I did get a hold of an Ashdown representative, who was fantastically helpful. I am pretty sure I fixed the problem (with his (and your!) invaluable help, of course!) and I'll post what I did after a couple of days, just to make sure the amp keeps truckin' and in case anyone else goes to scour the internet to fix this same problem.

G'day docSanchez, I'm just wondering how you got on with your Amp repair. I have the same problem with my Five Fifteen, i.e. TIP142 and TIP147 have shorted between the Collector and Emitter. The emitter resistors are 0.22 Ohm. I have emailed Ashdown to see if they could send me details of the mod but I've heard nothing back. Are you able to post details of the modification you did to your amp. Thanks alot mate

[docSanchez]

Well, for a start the emitter resistors are supposed to be 0.33 ohm. The only other problem on my amp is there is apparently supposed to be a jumper from R27 to the emitter of the TIP142 (TR2).

I used the contact hole for the emitter of the BDX53 (which isn't there in the Five Fifteens) for one end of the jumper, as this connects to the end of R27 and squeezed the other end of the jumper into the hole for the emitter of the TIP142 and soldered those two together. It would appear R27 leads into a circuit protection system, so if your amp (like mine) is lacking this connection then check for that.

Other than that, I haven't had to do anything. The only reason I never did a wrap-up post here is because (like an idiot) I fried my new TIP142 on accident and hadn't ordered a spare, so I had the amp fully functional for a couple of hours and then I blew it up again due to my endless need for tinkering and SCIENCE. So I hope this helps.

[reddwarfer29]

Thanks very much for the quick response docSanchez, much appreciated. If this is a common fault with the Five Fifteen amp you would think that Ashdown should doing a recall to fix it, even if they are out of warranty.

I'll try modifying my Amp this week and post back the results, thanks again for your help.

[reddwarfer29]

G’day docSanchez,

I am just posting back the results from the modifications outlined above, unfortunately the amp blew again after about 5 hours of use with the same results as before i.e TIP142 and TIP147 have shorted between the Collector and Emitter which cause the fuse to blow straight away on power up.

I managed to track down one of the local Ashdown reps and he sent me step by step instructions, good news is after doing these modifications the Amp now works perfectly. Here’s what to do:

1. Removed and discarded TR2, TR3, TR8 and TR9, then clean off the heat sink.
2. Fit a TIP142 in place of TR2 and a TIP147 in place of TR9 using Silicon pads (or Mica washer and heatsink compound ). Do not fit any components for TR3 and TR8.
3. Replace R22 and R38 resistors with the new 0R33 ( 6 watt ) resistors
4. Please ensure there are no resistors fitted in positions R24 and R36.
5. Fit a wire link between the solder pad where TR3 and R24 join; and the solder pad where TR2 and R22 join..
6. Change resistor R30 from 2K2 to 1K5 .
7. Turn the amp on with an 8 ohm load connected to the output, but with no input.... measure the voltage across R22 and R38 with a DC milli-voltmeter and adjust preset P1 for 3 mVolts on whichever is the lower, they should be between 2.5 and 3.5 mVolts.
8. Inject a signal into the input and test as usual, then play.

Hope this information helps.

[docSanchez]

This is a fantastic resource for people with older Five-Fifteens as it is a clear, step-by-step instruction to bring the amp up to standards and to a place where it will stop blowing itself up.
Sadly, my amp already has everything you already mentioned as it is new enough ;(
The only thing it didn't have was the wire link which I added in an earlier post.

So what I have found is I have a new problem: my transformer is shot. I have no earthly idea how this happened; but one of the solder terminals on the transformer came out from the winding.

Can anybody help me find a new/replacement transformer? The amp tech told me the "transformer is a 100VA unit with one centre tapped secondary ( 31 - 0 - 31 volts )..."
Unfortunately, I am still pretty new to transformers. On the transformer that came out of the amp it is labeled

120V - 100V - Fuse
YW PT-Five-Fifteen-100/120V
31V - 0v - 31V

These are the transformers I found:
Hammond 166E30 166E30 Hammond Manufacturing Transformers
Hammond 166F30 166F30 Hammond Manufacturing Transformers
Hammond 166G30 166G30 Hammond Manufacturing Transformers

I can't tell the difference between any of them. There's also this one:
Hammond 165530 http://www.alliedelec.com/search/pro...6250#tab=Specs

I don't think the last one is what I need, (also it's more expensive) The only thing that confuses me about the first 3 transformers is that they have 5 cables going out: 2 for the primary winding and 3 for the secondary winding; both ends and a center tap. The transformer that was actually in my amp has 6 cables/junctions coming out from the transformer, and though one of them was unused and covered with heat shrink tubing, it still makes me pause.

Any transformer experts out there willing to give me a hand?

[Markcm]

1. Removed and discarded TR2, TR3, TR8 and TR9, then clean off the heat sink.
2. Fit a TIP142 in place of TR2 and a TIP147 in place of TR9 using Silicon pads (or Mica washer and heatsink compound ). Do not fit any components for TR3 and TR8.
3. Replace R22 and R38 resistors with the new 0R33 ( 6 watt ) resistors
4. Please ensure there are no resistors fitted in positions R24 and R36.
5. Fit a wire link between the solder pad where TR3 and R24 join; and the solder pad where TR2 and R22 join..
6. Change resistor R30 from 2K2 to 1K5 .
7. Turn the amp on with an 8 ohm load connected to the output, but with no input.... measure the voltage across R22 and R38 with a DC milli-voltmeter and adjust preset P1 for 3 mVolts on whichever is the lower, they should be between 2.5 and 3.5 mVolts.
8. Inject a signal into the input and test as usual, then play.

Great post guys, thank you.

I'd like to point out that in the last step when you measure across the output resisters R22 and R38 to adjust P1 to achieve 3mv across the lowest value resistor, the voltages will be opposite polarity. I emailed Ashdown and they promptly confirmed that is correct; just treat it as absolute voltage, regardless of polarity.

Thanks again for this thread, my Five Fifteen amp is now working again.

[Enzo]

Hi Markcm, welcome to the forum.

You are right to point out that polarity is important.

However in this case, the requirement is to measure the voltage across a part. Unless you also specify which end is which, there will not be a polarity. In other words of there is 1 volt across a resistor, it will be 1 volt regardless of which direction you take the reading. One end will be positive with respect to the other end. Of course then one end is negative with respect to the other end.

In these amps, voltages are usually measured with respect to ground. SO if one end is at zero, and the other end at +5mv, then we can say there is +5mv at the one end, and 5mv across the part. Reading the voltage across the resistor is just a way to infer the current flowing through it. If you swap your leads, the polarity reverses.

I realize I am being very picky about terminology, and someone may well disagree with me.

[Markcm]

Hi Markcm, welcome to the forum.

You are right to point out that polarity is important.

However in this case, the requirement is to measure the voltage across a part. Unless you also specify which end is which, there will not be a polarity. In other words of there is 1 volt across a resistor, it will be 1 volt regardless of which direction you take the reading. One end will be positive with respect to the other end. Of course then one end is negative with respect to the other end.

In these amps, voltages are usually measured with respect to ground. SO if one end is at zero, and the other end at +5mv, then we can say there is +5mv at the one end, and 5mv across the part. Reading the voltage across the resistor is just a way to infer the current flowing through it. If you swap your leads, the polarity reverses.

I realize I am being very picky about terminology, and someone may well disagree with me.

I'm sorry but I don't think your comments aid to this five-fifteen amp repair discussion at all. My intent was to help others who may have ended up here, possibly from a google search, trying to fix their five fifteen amp. No offense intended but your comments about voltage, current, swapping leads and "reversing" polarity neither aid to this repair or in my opinion are very clear/concise. My main goal was to point out that these two resistors share a common point in the circuit so they will most likely be measured with the same "relative" reference which will result in opposite relative polarities which I feel is an important detail and will help clarify if one has been "successful" with their repair. That was my intent.

I don't mean to step on your toes as a major contributor to this forum (all respect for your contributions) anymore than you intended to step on mine although I feel like you derailed my comment which was short, accurate, relevant, and simply intended to assist any and all with a successful Five-fifteen amp repair.

[Enzo]

I apologize if you felt I intruded on your comments, not my intent at all.


My intent was to explain to others reading along, essentially what you report Ashdown as telling you - "just treat it as absolute voltage, regardless of polarity." I used different terms in hopes someone who doesn;t get it one way, might get it another way. Much as you added to the previous post by reddwarfer with further explanation.

[Phostenix]

Good to see you're back, Enzo. We missed you for a few days here. Well, SOME of us missed you.

[diydidi]

Anyone have schematic for me please!!!!????

[Jazz P Bass]

http://music-electronics-forum.com/a...ss-amp-sch.jpg

Here is a doc that I copied off of a post in 2010.
It has to do with modding the output section on older 515's.

[diydidi]

Anybody have a schematic???

[J M Fahey]

Anybody have a schematic???

Here it is

WARNING: THE VERBAL (WRITTEN) INSTRUCTIONS DO *NOT* MATCH PARTS NUMBERING IN THE SCHEMATIC.

[J M Fahey]

UPDATE:

I searched my small Ashdown schematic database and found one which matches written instructions.

It is NOT labelled "515" BUT itīs quite common for manufacturers to build a few of the "new" models using leftover parts of the earlier ones they replace, specially since often "new" models are just cosmetic rehashing of earlier successful ones, simply under pressure from Marketing Department guys.
As in: "Hey !!! , we need FIVE new models for Cristmas (NAAMM/Frankfurt) , we canīt push las year models !!!!" .

So here it is the Backpack, with that silly mixture of BDX and TIP transistors.
What were they trying to do?
Emulate Mesaīs dubious "Simulclass" tube mixture?