Spectral dma 260 hum

[fas42]

Just tuned into this, and haven't read every post, but information in this link may be useful to some: Mains DC and Transformers, http://sound.westhost.com/articles/xfmr-dc.htm. A good DIY solution that I've tried ...

Frank

 

[Mmizner]

I was wondering if there is any new information on the DMA-260 transformer hum issue? Is it true that Spectral acknowledges that there is a problem and is working on a fix?
I've got one on order, scheduled to be delivered in about six weeks. If Spectral still working through the problem, i would prefer to delay my delivery until the issue has been resolved.

 

[gratefulgroveway]

Hi,

The news is frustrating. My dealer has had long conversations with SPECTRAL who do, I am told, know there is a problem. They have two fixes - one is to re secure the power supply and the other is to fit a new top plate without slits. Or that is what I understand. When this will be done I don't know and am pretty shocked by how slowly SPECTRAL have moved.

I hope that helps but my view is that the company are being pretty careless about support and am no longer a lover of the brand - even though the sound they make is good.

 

[ack]

My suggestion would be to go ask and demand from your dealer to have a conference call with their Support, and directly understand the issue, solutions and reason for delay. I would say your dealer is not aggressive enough on this issue and you are rightly disappointed.

The solutions you describe above basically tell me there is nothing they can do electronically and they just want to muffle the noise by either tightening bolts and/or closing top-plate gaps from where noise can escape - essentially, trap the noise. As such, they probably don't consider this very much of an issue, or again, your dealer hasn't made it clear how important it is to you, or they think part of the problem is partly with your electrical supply...

 

[gratefulgroveway]

Thank you for this. I understand that SPECTRAL do know there is a problem. I think it is common in 240V. I am going to let my dealer do the next round. If things improve so be it. If not I will take up your advice.

Thanks

 

[gratefulgroveway]

I have now received a new top piece for my 260 from SPECTRAL. This has no slits and has made a considerable improvement. I understand that there are other modifications in the pipe-line.

Thanks

 

[ack]

I wouldn't trust it, long term, because of the increased internal heat dissipation in this model.

 

[gratefulgroveway]

Really, Ack?

I can't imagine a company like SPECTRAL would issue a solution that will damage the product?

 

[ack]

1. Why would they have a different cover in this model in the first place? I think the answer is obvious
2. They have made such mistakes a number of times in the past, like the SDR-2000's power supply that comes to mind, and also the 2000's sorbothane feet that would eventually melt - both of which I suffered through and the units were ventilated as required. I see no adequate long term heat testing, but it also depends what the average ambient temperature is. For example, my 360s run too hot to touch in the summer, just fine in the winter.

I see this as a temporary solution, and I hope they do too. Perhaps the other changes in the pipeline that you mentioned may include reduced bias for less heat dissipation??? Or fans? Don't know. But having seen what I have seen the past 20 years, ANYTHING that has to do with heat dissipation in Spectral products makes me wanna be very careful. For what's it worth, I run a fan on top of my 30SL to cool the top plate, irrespective of the fact it has no cutouts - you can see it in my system's pictures; it also is too hot to touch in the summer, without it. Remember - nobody's perfect.

 

[Mmizner]

Spectral DMA-260 hum

I thought I would update everyone on my new Spectral DMA-260.
It arrived a little less than two weeks ago and I purposefully waited before posting so i could become more familiar with the new unit and be certain of my impressions.
I had posted about a month ago while I was waiting delivery and expressed a concern about the hum issue talked about in this thread.
What made me very concerned was that my previous amp had a very loud transient buzz. it made my listening sessions almost unbearable.
I'm happy to say that my new DMA-260 and DMC-30ss II are absolutely dead quiet.
These are the first spectral products I've owned and so far, i'm very impressed with both the build quality and sonics.
To determine if the unit hummed, I put my ear right up to the amp so I could detect even the most subtle buzz or hum.
I did talk to my dealer about the problems reported on this forum and he surmised that it was a volatage/frequency mismatch issue.
my unit does have the slots cut into the top cover.
additionally, i've been corresponding with another audiophile who also purchased a new DMA-260. we've traded e-mails after our amps arrived and his is also quiet.
BTW, we both live in the states.

 

[kee]

Just received my DMA-260 220V version. No transformer hum issue.

 

[gratefulgroveway]

Where are you Kee? just interested about the voltage issue and this hum

Thanks

Paul

 

[kee]

Where are you Kee? just interested about the voltage issue and this hum

Thanks

Paul

I am staying in Singapore. Just received my DMA-260 few weeks ago. No transformer hum issue.

 

[nirodha]

I am staying in Singapore. Just received my DMA-260 few weeks ago. No transformer hum issue.

A friend of mine has a transformer hum and we live in the Netherlands....this could make it a "European situation"

 

[gratefulgroveway]

I have had a very helpful correspondence with SPECTRAL about this problem. It does seem that European 240V is rattling the power supply - I'm no electronics expert - and that they are working on a solution.

I will keep talking to them until we get this problem sorted as at the moment the lovely amp isn't working as it should!

I wonder has anyone put the new 30SS into their system alongside the 260? Is it that much better than my late model standard 30SS?

 

[kee]

I am using DMC-30SS Series 2 with DMA260. I did home trial the the original DMC-30SS last year. Based on my memory, the DMC-30SS was more dark sounding while the Series 2 is more airy and transparent.
Take it with a pinch of salt though as it has been a while...

 

[gratefulgroveway]

But you like DMC-30SS Series 2 ? I am told it is a big break through but...

Paul

 

[kee]

But you like DMC-30SS Series 2 ? I am told it is a big break through but...

Paul

Yes, I like the DMC-30SS Series 2 a lot. Beside very transparent sounding, it is also very dynamic. Per what I posted earlier, I had some reservation on the dark sounding character of the original 30SS. But thats not the case for the Series 2. It matches perfectly with the DMA-260. All the audiophile that came to listen my system were very impressed.

By the way, my speaker is Avalon Indra

 

[ack]

But you like DMC-30SS Series 2 ? I am told it is a big break through but...

Paul

It's a huge breakthrough; fear not.

 

[kee]

I read that spectral is going to offer upgrading option for current DMC-30SS.