The spectral adventure - part 2

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
Having previously started a discussion concerning experience when trying to obtain simple information from Spectral and being refused because there is no distributor in the UK, I would like to continue reporting but consider a new topic is now more suitable and will also avoid it being buried in the older thread. I also wish to be fair, in as much as not only to complain about what needs improving but also say what is right. I went ahead and bought the DMC 30S. A thirteen year old item but apparently little used. Expensive in the UK. It was 220 volts so I also had to buy a power regenerator to stabilise output voltage, as it would cook long term in the usual 240 to 250 volt environment here. As previously mentioned, my interest in Spectral stems from firstly having discovered RR records and then their cds many years ago and having heard their equipment at shows around the world over many years. This preamp has not disappointed in any way. It is everything a pre should be and has fundamentally changed the way my system sounds. It does have to be kept on all the time and it does take a long time to settle down if ever switched off. The regenerated pure sine wave mains power, at a constant 230 volts, helps a lot with all the front end equipment. One thing sums up my experience with this, my first Spectral item : I was listening to a RCA cd from the Artur Rubinstein boxed set the other night and realised I was listening to a Grand Piano playing in my room; I was not listening to a Grand Piano playing in my room through speakers. It was as if those funny boxes in the room were not doing anything. That is a subtle but profound difference. The system is really fun now and goes to realistic SPL without getting compressed or distorted. So, I have no doubt that, technically, Spectral are superb. They design and manufacture exceptional product - exactly as I always had assumed - and why I have persevered so much to become an owner. The Dutch distributor very kindly solved the issue of no UK distributor. Now all I need is a DMA 250 power amp........
 
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dan31

Well-Known Member
Jul 22, 2010
1,016
365
1,153
SF Bay
Glad to hear you found away to use the Spectral preamp and the music you enjoy! Many if us are enjoying the DMA-260, maybe you can pick up the amp when someone upgrades to the DMA-300. In the meantime enjoy your system and the music.
 

LL21

Well-Known Member
Dec 26, 2010
14,411
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Great news and congrats. Nothing like a great dealer to look after you. Hopefully, he can find you that spectral power amp now!!! ;) Enjoy.
 

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
Thanks. Nice system you have there. I also use Velodynes and Entreq and Stillpoints. How do I get my equipment list to show as a footnote to posts, as you have done ?
 

LL21

Well-Known Member
Dec 26, 2010
14,411
2,509
1,448
Thanks. Nice system you have there. I also use Velodynes and Entreq and Stillpoints. How do I get my equipment list to show as a footnote to posts, as you have done ?
Click on top right hand corner of the main menus where you see "Settings". Then along the left, you will see an option to Edit Signature. If you add 'bold' to the words you wish to bold, that's about it...it will look like the other signatures you see. Hope that helps. Look forward to reading your signature and system!
 

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
Click on top right hand corner of the main menus where you see "Settings". Then along the left, you will see an option to Edit Signature. If you add 'bold' to the words you wish to bold, that's about it...it will look like the other signatures you see. Hope that helps. Look forward to reading your signature and system!

Did it - thanks. No bolds cos struggled to fit all into 500 characters. I think you will get what is going on.
 

kennyb123

Well-Known Member
Nov 30, 2012
856
796
1,155
Kirkland, WA
I love my 30S! Glad to hear it impressed you as well. Mine is paired with a DMA-150 Mk2, which I purchased at the same time.
 

DRC

New Member
Aug 21, 2014
30
0
0
Hong Kong
Congrats dgw! I m new to this forum but have been a long term Spectral fan. I used to live in London in the 90s and was such a big fan of Spectral that I shipped my own DMA 80 from Progressive Audio in Ohio to the UK and ran it through a transformer for years! At that time, I already had a Krell KSP7B preamp so I had the most unusual set up of a Krell pre and Spectral power combo. Fortunately nothing blew up and I am still alive to tell the tale! I remember the sound to be very fast, transparent just lacking a bit in bass.
 

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
Congrats dgw! I m new to this forum but have been a long term Spectral fan. I used to live in London in the 90s and was such a big fan of Spectral that I shipped my own DMA 80 from Progressive Audio in Ohio to the UK and ran it through a transformer for years! At that time, I already had a Krell KSP7B preamp so I had the most unusual set up of a Krell pre and Spectral power combo. Fortunately nothing blew up and I am still alive to tell the tale! I remember the sound to be very fast, transparent just lacking a bit in bass.

Thanks - just got a DMA 250 ! So now on full Spectral amplification ! Are you are on valves in Hong Kong? I buy valves for my Phono Stage whenever I drop by in HK !
 

DRC

New Member
Aug 21, 2014
30
0
0
Hong Kong
Thanks - just got a DMA 250 ! So now on full Spectral amplification ! Are you are on valves in Hong Kong? I buy valves for my Phono Stage whenever I drop by in HK !

That's great that you have an all Spectral amplification system...now just work on the MIT cables! :) I am based in Hong Kong and am a newbie to tubes so believe it or not, I buy my valves from the US...I do have dealer contacts here that can get me great tubes but I haven't used them yet.
 

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
That's great that you have an all Spectral amplification system...now just work on the MIT cables! :) I am based in Hong Kong and am a newbie to tubes so believe it or not, I buy my valves from the US...I do have dealer contacts here that can get me great tubes but I haven't used them yet.

All interconnects at now Mit-Spectral and changing from Transparent Audio Speaker Cables to Mit-Spectral soon. Only issues I have is (1) very low level, constant hum and (2) cannot change Phase ( polarity) without switching off power amp first because of nasty crack through speakers. I am hoping that Mit-Spectral speaker cables will fix both these issues ? I buy my NOS GE tubes in HK from WiWi in Central - awesome stock and such a kind gentleman. Rumi too ! HiFi is very philosophical.
 

DRC

New Member
Aug 21, 2014
30
0
0
Hong Kong
All interconnects at now Mit-Spectral and changing from Transparent Audio Speaker Cables to Mit-Spectral soon. Only issues I have is (1) very low level, constant hum and (2) cannot change Phase ( polarity) without switching off power amp first because of nasty crack through speakers. I am hoping that Mit-Spectral speaker cables will fix both these issues ? I buy my NOS GE tubes in HK from WiWi in Central - awesome stock and such a kind gentleman. Rumi too ! HiFi is very philosophical.

Cool, my office is in Central, I will definitely look him up!!! I am sure that we could probably talk for hours about philosophy, life, politics over a glass of Musigny listening to music- I certainly find certain types of music deeply inspiring...I don't profess to be a technical expert as there are many "true experts" here but I wonder if "grounding" can solve your hum issue. It could also be related to your transformer as I too remember having a hum issue in the past.
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
1,198
580
Boston, MA
Thanks - just got a DMA 250 ! So now on full Spectral amplification ! Are you are on valves in Hong Kong? I buy valves for my Phono Stage whenever I drop by in HK !

I am glad the dealer is taking care of you! I have fond memories of my 250... How's the sound so far? Does it meet your expectations?
 

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
I am glad the dealer is taking care of you! I have fond memories of my 250... How's the sound so far? Does it meet your expectations?

So far, the sound is very good. Still waiting to change Speaker Cables from the present Transparent Audio to Mit-Spectral UL 38HD SIII and am hoping that will make the final difference in dynamics, resolution and transparency.
Also will have to see if the Mit-Spectral Speaker Cables will stop the constant low level hum - it is inaudible on the left channel from 3 ft away but audible on the right channel up to 12ft away. Another issue is the Phase change which produces a nasty crack through the speakers even on Mute, even with no source connected. Moved the power supply for the DMA 250 which was into its own separate wall socket to the same socket as the source components and that improved the hum a lot but it is still there. Separating power lines, speaker cables and interconnects - as Spectral Manual indicates - is not completely possible in the present setup. Waiting for Mu metal strip and anti interference fleece to arrive to see it that will help the hum issue. Any suggestions appreciated!
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
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580
Boston, MA
So it's not clear how your system is wired up (signal and power cables) in order to offer any concrete suggestions re: the hum. Regarding the phase change, I am also not clear where you are attempting to change that, thus no idea what the source of the nasty thump you are describing. In all likelihood, you have a ground loop somewhere, and I have to assume you started having this after buying the Spectrals, or it's not clear if that's not even the case. Standard operating procedure: for starters, make sure you star-ground all equipment to one power distributor, using equal length (and optimally, same brand/model) power cords and even interconnects; also test for continuity between the ground plugs of each power cord, and somehow assert they make contact with every component's ground prong. Other standard questions: do you get the hum from all inputs and all sources? Or is this something that, say, only your phono would exhibit (in which case it may be an entirely different beast, depending on how well your phono is shielded, and what the ground connections in that apparatus look like). Replacing the speaker cables should not have an effect on hum, but replacing interconnects (and what are they now, MIT? your signature seems to conflict with what you are describing, in that it doesn't mention Transparent cables at all) may, if your cables have a wire disconnected somewhere or something, or if we are talking about phono only, perhaps the phono interconnects are not shielded properly - again, phono would be an entirely different beast.
 

edorr

WBF Founding Member
May 10, 2010
3,139
14
36
Smyrna, GA
So far, the sound is very good. Still waiting to change Speaker Cables from the present Transparent Audio to Mit-Spectral UL 38HD SIII and am hoping that will make the final difference in dynamics, resolution and transparency.
Also will have to see if the Mit-Spectral Speaker Cables will stop the constant low level hum - it is inaudible on the left channel from 3 ft away but audible on the right channel up to 12ft away. Another issue is the Phase change which produces a nasty crack through the speakers even on Mute, even with no source connected. Moved the power supply for the DMA 250 which was into its own separate wall socket to the same socket as the source components and that improved the hum a lot but it is still there. Separating power lines, speaker cables and interconnects - as Spectral Manual indicates - is not completely possible in the present setup. Waiting for Mu metal strip and anti interference fleece to arrive to see it that will help the hum issue. Any suggestions appreciated!

I had a nasty hum on my DMA 360 monoblocks, that could not be solved using any of the suggestions offered in the Spectral manuals, short of the last resort solution, which is to lift ground using cheater plugs. This solved the problem. Apparently Coopersark is doing the same, and it is a "Spectral approved" practice.

Very unlikely cabling will solve the issue.
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
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Boston, MA
When it comes to hum, I've always felt lifting the ground should be the last resort... I feel the ground loop has to be identified and fixed, phono properly grounded and shielded etc, then ground could be lifted in order to improve things sonically even further (by preventing sensitive components from taking on ground-induced noise, such as phono stages), not as a measure to kill hum as the primary goal. This is Spectral's approach as well, I believe: in the 400RS and 300RS amps, there is an internal switch to deal with hum (I was talking to them about this recently, in fact); beyond that, lifting the ground at the plug is primarily for sonic reasons and to move the star-grounding location to the preamp (though the danger there is that the interconnects may not be able to carry large instantaneous current in case of fault, and risk melting).
 

edorr

WBF Founding Member
May 10, 2010
3,139
14
36
Smyrna, GA
When it comes to hum, I've always felt lifting the ground should be the last resort... I feel the ground loop has to be identified and fixed, phono properly grounded and shielded etc, then ground could be lifted in order to improve things sonically even further (by preventing sensitive components from taking on ground-induced noise, such as phono stages), not as a measure to kill hum as the primary goal. This is Spectral's approach as well, I believe: in the 400RS and 300RS amps, there is an internal switch to deal with hum (I was talking to them about this recently, in fact); beyond that, lifting the ground at the plug is primarily for sonic reasons and to move the star-grounding location to the preamp (though the danger there is that the interconnects may not be able to carry large instantaneous current in case of fault, and risk melting).

I simply had no other way to get rid of the hum.
 

dgw

Well-Known Member
Sep 10, 2014
36
0
236
England UK.
So it's not clear how your system is wired up (signal and power cables) in order to offer any concrete suggestions re: the hum. Regarding the phase change, I am also not clear where you are attempting to change that, thus no idea what the source of the nasty thump you are describing. In all likelihood, you have a ground loop somewhere, and I have to assume you started having this after buying the Spectrals, or it's not clear if that's not even the case. Standard operating procedure: for starters, make sure you star-ground all equipment to one power distributor, using equal length (and optimally, same brand/model) power cords and even interconnects; also test for continuity between the ground plugs of each power cord, and somehow assert they make contact with every component's ground prong. Other standard questions: do you get the hum from all inputs and all sources? Or is this something that, say, only your phono would exhibit (in which case it may be an entirely different beast, depending on how well your phono is shielded, and what the ground connections in that apparatus look like). Replacing the speaker cables should not have an effect on hum, but replacing interconnects (and what are they now, MIT? your signature seems to conflict with what you are describing, in that it doesn't mention Transparent cables at all) may, if your cables have a wire disconnected somewhere or something, or if we are talking about phono only, perhaps the phono interconnects are not shielded properly - again, phono would be an entirely different beast.

To answer your questions in detail :
All interconnects are Spectral-Mit except to Satellite Box and to Oppo BluRay. ( considered unnecessary extra cost )
Present speaker cable is TA but I am waiting for new Spectral-Mit Speaker Cable. I will have new Spectral-Mit Speaker cables in about 6-8 weeks. My Signature is ahead of the facts and I apologise if that was confusing.
All is grounded to one power distributor and all grounding on the plugs is correct.
Power cables are not all the same length and they are not all the same brand. The PowerAmp is on MIT Z cord which it is supposed to enjoy.
The "hum" is constant on all sources and on no source and does not change with volume settings.
There is no wire disconnected somewhere.
The Hum is worse on the right hand speaker ( 50db @ 1 ft ) than the left speaker ( 36db @ 1ft ).

The "Phase" issue refers to the "phase" button on the DMC 30S and its remote. This switches "Absolute Polarity" to the speakers. ( inverts polarity ).
Using this "phase" button to switch polarity / phase produces the nasty crack through the speakers.
I do always find significant difference with correct or incorrect phase settings and do check all new recordings where I do not already know what setting that producer uses. In those cases, the only way to tell which phase is correct, is to toggle on the fly while music is playing - something which is currently impossible - one would simply not dare do it. The only day to change phase currently is to turn Power Amp off, change phase, turn Power Amp back on.

It is useful to understand that the new Spectral-Mit speaker cables will NOT change the Hum issue nor the Phase issue because now I don't need to wait for those cables to arrive to find out !

So, I now have 3 questions from all this :
1. It would be very useful to know if the "hum" problem indicates something wrong with the Pre Amp or the Power Amp because both are under warranty at the present time but not for much longer.
2. Likewise, it would be very useful to know if the "Phase" issue indicates that something is wrong with the Pre Amp or with the Power Amp.
3. I live in England where we are on 240 volts nominal. All the front end components including the Pre Amp are on constant 230 volts regenerated sine wave power. The Power Amp is on the 240 Volts nominal and is a 240 Volt version. One would not normally "lift the ground" in the UK 240 volt environment. In fact, I have only ever seen manufacturers warning of doing this and insisting on mains power grounding. Is it safe and in order to lift the ground on the DMA250 when it is running at 240 Volts ? If this cures both issues it would be great but of course not if it is dangerous and not recommended practice.

Many thanks indeed !
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
6,774
1,198
580
Boston, MA
This is a tough one; it feels the preamp may be to blame, judging from the fact that the phase switch should not be causing this huge thump - in fact, none of the 5 Spectral preamps I've had over the last 20 years exhibited such a problem. It may be causing the hum as well, so I would suggest talking to the dealer about it, or, ahem, the factory. It doesn't feel lifting the ground will do much, if the hum is different between channels... As I said when you first wrote about your experience with the factory, your bigger problem is going to be servicing your equipment - let's see how this now plays out, and we hope the dealer will help...
 

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