Avondale SE200 Announcement on FB
- Thread starter Richard Lines
- Start date
laverda
pfm Member
The SE200's are available as a ready built boards for the discerning DIYer. The SE230 and SE400 are Avondale fit only or a finished RMS amp.
James Evans
Bedroom Bodger
Well after over a year of these boards being sat here looking at me I've finally got round to building an amp. It didn't blow up on switch on, that's a positive. Transformer buzzes like a hive however, which is not ideal. No difference on a dc blocker. Left channel has a mains/transformer buzz frequency hum, low level, but clearly audible at the speaker. Right channel quiet. Both channels play music, another positive! First impression after about 10 minutes of music, sounds different to the Qudos amp that was there for the past god knows how many years.
Mynamemynaim
38yrs a Naim owner
Also looks like you have multiple earth wires to various points on the casing.
Might be worth looking at those too especially on bolt together cases ?
Might be worth looking at those too especially on bolt together cases ?
James Evans
Bedroom Bodger
Hi Graham
I've always worked off the wiring on this voyager tbh:
Detail of an early Voyager amp – AVONDALE AUDIO
avondaleaudio.com
The speaker 0v and velleman 0v are connected to the transformer end of the cap6. Is that not the done thing? I've done this in all my amp builds up to now I think,
My thinking at the moment is the audible hum (one channel only) is directly related to the transformer buzz (dual centre tapped secondaries). Richard also seems to be seeing something similar in his amps using these transformers, although slightly less audible it seems. The transformer buzz on mine is LOUD!
I've braided the secondary wires, could that be causing some effect that the transformer doesn't like?
James
James Evans
Bedroom Bodger
Not sure what you mean? There's only a single mains earth connection to the chassis.
Richard Lines
pfm Member
Well done James.
I wonder how many others out there have 'bitten the bullet' and bought an ETC transformer.
Shielding is going to be an issue. I still need to look at my situation.
"The transformer buzz on mine is LOUD!" If that is a mechanical "buzz' then it sounds like it needs to go back to ETC!
"The speaker 0v and velleman 0v are connected to the transformer end of the cap6" - if you look at pictures of more recent builds AA do seem to be using the clean end currently. It's what I'm using on all my SE builds if only because it seems to make sense to do so - it is something Doug Self promotes.
Regards
Richard
James Evans
Bedroom Bodger
Hi Richard, yes, mechanical buzz from the transformer. Luckily they are only 25 mins down the road so I can drop it off if need be. I'll try re-routing the 0v wires but these cap boards only have 4 tabs at the clean end, 3 of which are already taken by the 0v wires from the SE boards. There is a tab I can use in the middle of the caps. The tabs on these are very tight together and fitting 4 next to each other is going to be a squeeze.
James
laverda
pfm Member
James,Hi Graham
I've always worked off the wiring on this voyager tbh:
Detail of an early Voyager amp – AVONDALE AUDIO
The speaker 0v and velleman 0v are connected to the transformer end of the cap6. Is that not the done thing? I've done this in all my amp builds up to now I think,
My thinking at the moment is the audible hum (one channel only) is directly related to the transformer buzz (dual centre tapped secondaries). Richard also seems to be seeing something similar in his amps using these transformers, although slightly less audible it seems. The transformer buzz on mine is LOUD!
I've braided the secondary wires, could that be causing some effect that the transformer doesn't like?
James
Try moving the SPK 0v to the clean ends.
The SPK protection 0v should not have any influence. You can try only using one SKP protect module too, you take a wire from both PSU 0v (dirty end) to the ref pin on the module, worked for me on many occasions.
The fact you're getting transformer noise in only one channel is odd as both channels look to be wired the same.
My ETC transformers don't hum (cant say its a buzz) with nothing on the secondaries, its only when you present a load that they hum and its inaudible at 2mtrs but it annoys me greatly as I know its there. I have other frames (EI) transformers which are completly silent in operation. I sent mine back to ETC and they reported they could'nt find anything wrong, they did 'double dip' with varnish which seems to have helped. And I do believe as time has gone on and in use they are getting quieter only a 'faint ' hum now.
The sonic benefits are very good IMO and having two in the one case = double trouble.
Graham
James Evans
Bedroom Bodger
I'm wondering if it's an issue with the secondary feeding that one channel, because as you say, wiring is identical on both. I've mailed ETC anyway as the transformer noise as it stands is not workable.
S-Man
StrivingON
I would only use the "dirty" end of the CAP6 for the transformer centre tap connections (as others have said).
It's worth checking your zobel resistors, particularly on the buzzy channel. Are they getting hot, has one failed?
Transformers "groaning" can be a sign of loads of current flowing = not good!
Stick a 'scope on the ouptut.
It's worth checking your zobel resistors, particularly on the buzzy channel. Are they getting hot, has one failed?
Transformers "groaning" can be a sign of loads of current flowing = not good!
Stick a 'scope on the ouptut.
Does it hum with the secondaries not connected?
James Evans
Bedroom Bodger
Not tried it unconnected yet, will give that a shot tonight.
No sign of anything getting even vaguely warm.
The buzz was there on first switch on when I was setting bias. At this point both CT secondaries were connected to the cap boards but only the right channel amp board was powered. No change to buzz when connecting left channel board for bias setup.
laverda
pfm Member
I agree with Richard, who else has gone down the ETC route? Im no expert but there is info on the net. If it's a buzz there is a possable winding issue, hum is slightly different I believe it may be under wound primaries.
Ive had this in the past (as many others have) with off the shelf toroidal's with 230v rated primaries running off 240v. My mains is 244ish. This is what I may have with my ETC's Tx's or rather the symptoms sound like it...
I could be wrong.
Ive had this in the past (as many others have) with off the shelf toroidal's with 230v rated primaries running off 240v. My mains is 244ish. This is what I may have with my ETC's Tx's or rather the symptoms sound like it...
I could be wrong.
James Evans
Bedroom Bodger
I have one of these here that I was originally intending using in this amp:
(how expensive are transformers these days!!!)
I may drop it in and see how it compares. Aside from the transformer noise the amp is sounding very nice I should add!
I've got about 4mm clearance between the tx and case lid, I guess I could try some addis pads
(how expensive are transformers these days!!!)
I may drop it in and see how it compares. Aside from the transformer noise the amp is sounding very nice I should add!
I've got about 4mm clearance between the tx and case lid, I guess I could try some addis pads
Richard Lines
pfm Member
I'd suggest you could use a piggy back crimp terminal on one of the outer connectors which would give a you a fifth contact point - that is what I did with one case where I used the HackerCap PCB's.
Regards
Richard
laverda
pfm Member
I have one of these here that I was originally intending using in this amp:
(how expensive are transformers these days!!!)
I may drop it in and see how it compares. Aside from the transformer noise the amp is sounding very nice I should add!
I use Tiger Toroids (Steve) he will make you a bespoke transformer: Which has oversized cores with primaries wound for 240v or anything you like inc multi primaries if you want. Copper foil tape between the pri and secondaries and a mu-metal band on the outside wrapped in a silk finished in a color of your choice (I think he has 4 colors) and potted inserts to clamp type fixings.
500VA £100- £130 ish + shipping but I do tend to buy a few at a time.
Apologies if you already know all this.
Tiger Toroids is a British company offering a fast and flexible solution for transformers and sinewave inverters.
Tiger Toroids is a British company offering a fast and flexible solution for the development and supply of all sorts of transformers and sinewave inverters, transformer, toroidal, toroid, choke, winding, current transformer, line transformer, inverter, pure sinewave, custom winding, air core...
www.tigertoroids.co.uk
James Evans
Bedroom Bodger
Thanks, Tiger had sprung to mind, but I'm not giving up on this ETC one just yet. I'll test it with no load attached first. Might try some form of thin isolation pads underneath it, see if that at least stops the case amplifying it. ETC have said to get it back to them to test it, so I'll do that as a next step.
OzBrit Audio
pfm Member
James I'd be really interested to hear in your thoughts between the Qudos and the SE200's (after you sort your hum problem out) and particularly how the ETI transformer sounds compared with the RS Components toroidal?
laverda
pfm Member
I ended up using some tap washers as a buffer between the Tx chassis and case..it did help.