[CButterworth]

Having finally "put-to-bed" so to speak the hum problems resulting from my homebrew tubed preamp, I am now plagued with "idiot-proofing."

There have been occassions on which I have almost switched off the preamp prior to the main amp (AKSA).  I do remember to switch on the preamp prior to the AKSA, and my wife has fully memorized the concept of AKSA on LAST, off FIRST.  Still, I get worried.

So, I am thinking that a solution would be to install a solid-state time delay relay in the AKSA.  Maybe 20 seconds.  The relay couldbe powered using the redundant 6.3VAC winding of my preamp HT transformer.  This transformer is already delayed 30 seconds using a tube delay / coil relay, triggered by switch-on of the preamp heaters.

So, the scenario would be:  1. switch on preamp; 2. after 30 seconds, the preamp HT is energized; 3. upon power-up of the HT transformer, the secondary winding would trigger the time delay relay in the AKSA; 4. After 20s, the AKSA would power-up.  NO SMOKE, but great sound.

OK?  So here's the crunch! 

Hence the QUESTION:

How would I power-off the system using the preamp switch?  If I set-up as detailed above, AKSA and preamp would power-down simultaneously.  I suppose the same would happen if the house power-supply was cut.  Anyway, would damage to the AKSA and / or speakers result from this ?

I'd appreciate any ideas, advice, etc.  As for the sound of my system - it is absolutely amazing (although I do need better speakers).

Charlie

system:
Rega Apollo
Aikido preamp - four 6SN7s
AKSA 55N
Polk rt600

[AKSA]

Hi Charlie,

Nice to hear from you - this is a curly problem but quite solvable.

Possibly the easiest way to do this would be via microprocessor, ATMEL or PIC.  The micro would cost a few dollars, a darlington chip could be used to amplify the power output to drive relays, and up to 8 relays (IIRC) could be controlled in any switch-on and switch-off sequence.

However, the catch is that you'd need to write some code in either C+ or Assembler.  I'm not a programmer, so can't advise on this, but there are plenty of guys who can and who could tell you how much work is involved.  It wouldn't be much, since the functions are simple.

You would need a permanent power supply for the micro, but this is routine and you've picked up on this already.

Anyone here willing to knock up the code?

Cheers,

Hugh 

[andyr]

Hi Charlie,

With respect, IMO you're trying to get yourself out of a hole you've dug yourself into. 

Yes I'm sure you can solve this problem but, if powering your Aikido preamp on and off produces a massive thump through your AKSA ... then mebbe you need to change your preamp for something which doesn't exhibit this problem ... like a GK-1?? 

I suggest that if you have a relay between your AKSA and the mains power, this will inevitably degrade the sound of the AKSA compared to a direct connection, like the rest of us have.

I keep my AKSAs on 24 x 7 ... but (to "save" the tube) I do power off my GK-1 when I've finished listening - unless I plan to listen again in a few hours.  I have Magneplanars which have a very delicate ribbon tweeter ... if the GK-1 exhibited a nasty power on/off thump then I would be stuffed!  But it doesn't!! 

Regards,

Andy

[CButterworth]

Hugh, Andy,

I have no idea if I have dug myself into a hole 

To be honest, I have never tried having the AKSA switched on before I switch on the preamp, or switching of the preamp prior to the AKSA.  I have simply always assumed that it is a "no-no"

Having said that, the Glass-ware blurb that John Broskie (Aikido designer) has on his site says this:

"No Popping Sounds at Startup, No Squirrelliness

Moreover, the Aikido amplifier does not make huge popping swings at startup, as the output does not start at the B+ and then swing down a hundred or so volts when the tube heats up, as it does in a ground-cathode amplifier. Furthermore, the Aikido amplifier seems to bypass much of the power supply squirrelliness, making the circuit sound as if it were attached to batteries or a well-regulated power supply."

I also know that when testing my Aikido using an SET, the SET owner wasn't concerned about switching the Aikido preamp on and off with the SET still powered.  On switch-on of the preamp B+, the sound seemed to almost fade-in, and on switch-off is did seem to fade-out.  BUT, a lot of folk have said that solid-state amps are less tolerant of voltage swings.

So, how can I check this without the AKSA / speakers being in danger?

Charlie

[AKSA]

Charlie,

Speakers can take monumental short term abuse.

You can test with the speakers in place.  These spikes seldom last more than 20mS, and won't damage anything.  They will give you quite a fright, certainly, but no damage will result.

Cheers,

Hugh

[andyr]

Having said that, the Glass-ware blurb that John Broskie (Aikido designer) has on his site says this:

"No Popping Sounds at Startup, No Squirrelliness

Charlie

Hi Charlie,

Sounds like you should be fine then!

BTW, WTF is "squirrelliness" re a power supply?        It's not a term I've encountered before! 

Regards,

Andy

[CButterworth]

Andy,

But what about switch-off?

I did consider the GK-1.  However, the US$ is taking a beating, and my real-life LifeForce Upgrade arrived in February, so I simply could not justify the expense of the GK-1.  The Aikido has cost less than the GK-1.  It may not sound as good, and the stress of designing the PSU and debugging ground loops left me fraught. However, it has allowed a great improvement in sound quality and left my dearly loved wife saying that we'll begin saving for the AKSA LifeForce Upgrade as well as a new house for our acre of land.

To be honest, I did feel like rather like a traitor to Hugh and his line of excellent products when I decided to build the Aikido.  Hugh, I humbly apologize for doing this and I will try to make-up for this in the future.

Incidentally, my three-month old loves the AKSA, especially his first CD which is a collection of lullaby covers of Pink Floyd music!

Regards,
Charlie

[andyr]

Andy,

But what about switch-off?

Incidentally, my three-month old loves the AKSA, especially his first CD which is a collection of lullaby covers of Pink Floyd music!

Regards,
Charlie

Aah, Mr Broskie doesn't make any mention of that?   

Then you might have a problem?  I know my active XOs make one hulluva thump if I'm stupid enough to turn them on/off while my AKSAs are powered up.  Still, the only driver in my Maggies which might blow is the ribbon ... as Hugh said, "normal" drivers should be able to take a 1/10th of a second spike, so you shouldn't have a problem.  And they ain't blown yet ... but I suspect you're gonna just have to "suck it and see"!   

Lullaby covers of Pink Floyd, eh!  Wow!     I know there was an album put out by some Brit orchestra doing "symphonic Floyd" but lullabies ... that's amazing!  Have you heard "Dub Side of the Moon"??  That's a great reggae cover (if you're into reggae!  ).

Regards,

Andy

[CButterworth]

Andy,

Well, I plucked up the courage to switch off the Aikido while the AKSA was still on.  There were no thumps, no nothing - Phew.

I suppose that I really now need to see if Broskie is correct about the start-up.  At least I feel confident that my speakers will survive pretty nasty stuff.

The lullaby covers of Pink Floyd is by a guy called Michael Armstrong.  He says on the cd blurb that the style of music by Pink floyd lends itself to the lullaby format played on various instruments such as glockenspiel, vibraphone, etc.  I have to admit I do actually quite like it, and it makes me laugh that my kid goes to sleep to a tune called Brain Damage!

At some point, I would love to listen to a GK-1 there are great things written about it.  I'll be demoing my AKSA / Aikido set-up over the summer to the Arizona Audiophile Club at one of their monthly meetings.  Regardles of their opinions, I'll still be intending to upgrade within the AKSA line.  Hugh has built up a dedicated suite of followers, his customer service is second to none, and his products (I have only heard the AKSA 55N, and the 100N) to my ears are outstanding.

Thanks for the advice, I feel much better about impending visit of the mother-in-law and the survival of my speakers.

Regards,


Charlie

[andyr]

Andy,

... and it makes me laugh that my kid goes to sleep to a tune called Brain Damage!

Regards,

Charlie

Hi Charlie,

You realise your kid is already on the "slippery slope to perdition" if he likes "Brain Damage" at - what did you say - 3 months?   

At kindergarten he'll be into acid and then when he's in his teens, he'll be trying whatever they've invented in the 2020s!!   

Regards,

Andy

[CButterworth]

Andy,

I have hopes that he'll be into Acetic Acid - with his fish and chips of course.  I shouldn't joke about kids and drug problems, it seems that people seem quite eager to peddle some pretty nasty stuff to very young kids these days.

Well, it seems that I shouldn't worry too much about the Aikido / AKSA combination.  I did try having the AKSA on first.  With my Aikido, it seems that there is a thump when the B+ gets switched on. I expect that this mainly results from diode-bridge rectification for the B+ which does swing up to voltage quickly compared with tube rectification. However, it is not all that bad.  Even though, it does still make sense to remain in the habit of switch-on sequence running from source equipment; preamp; amp; speaker, and off in the reverse order.  At least I know that should anyone get these out of order, the results will not be catastrophic.

Well, I suppose that I should go and play my three month old's next favourite CD - Ukele covers of the Grateful Dead 

Regards,
Charlie

[Seano]

I know that if I have the GK-1 switched on before the amp then I get quite a thump through the speakers and if I don't switch it off first I get much the same thump.

The Belkin PureAV power console http://catalog.belkin.com/PureAV_detail.process?Product_Id=254766 has programmable delays built in so that your equipment can be powered up and powered down in a cascade...



It might kill two birds with one rock....but for AU$860  .........it'd want to to!!! (apparently it's RRP is more like AU$1,300)

[CButterworth]

I have looked into the various power conditioners, etc.  The Belkin and the Adcom seem to do pretty much the same thing - they can perform sequential start-up with up to a 5 second delay.  This would not be enough considering that my tube heaters have a 30 second delay.  However, these units have inputs for a "trigger" that is either AC or DC.  I suppose I could use the 6.3VAC secondaries on my B+ transformer to trigger the 5 second delay for the AKSA.

I believe that used Adcom ACE conditioners can be purchased reasonably on either Ebay or Audiogon.

Well, I appreciate the input.  I am now not as worried as I was.  I'll have to take a look for used Belkins or Adcoms.

Regards,
Charlie

[DSK]

...I know that if I have the GK-1 switched on before the amp then I get quite a thump through the speakers and if I don't switch it off first I get much the same thump...

  Seano, did you mean this the other way around ... ie. if amp is already on, you get a thump when turning on the GK-1? 

[Seano]

  yeah, I reckon I might've...........

I'm working off distant memory because I haven't been using my AKSA combination in nearly 18 months.

A lousy listening set-up in the house (no chance of speaker alignment), un-resolved hum and packaging problems with the GK-1, the lack of time and dollars (ie. imperative) to fix them and an ever impending major renovation have confined them to a cupboard.  Audio duty is currently being provided by the old Yammy integrated....

Of course, getting the AKSA gear back on track once the yet to be started reno's are complete will mean an upgrade to the LF100 and the Platinum mod to the GK-1 (along with a new case and wiring).......one day!!!

[PSP]

Charlie,
Following a suggestion by TomS ( http://www.audiocircle.com/index.php?topic=39397.msg353471#msg353471 ) I bought the Belkin PF-60 for ~$180 including shipping at http://ecost.com/Detail.aspx?EDP=2634436 to handle the on/off sequencing for my Orions.  I also wanted to avoid the effects of rapid and uncontrolled power cycling when power is restored after a thunderstorm.

The PF-60 has six banks of outlet pairs (each pair filtered for digital, video, analog audio, etc. and two high-amperage outlets for power amplifiers) that can be set for "always on", "switched", or "delayed".  "Switched" comes on when you turn on the PF-60, and "delayed" comes on after the delay time = 5, 10, 15 seconds.  I have the HT Receiver and the sources "always on", the GK-1 is "switched" and the amps come on after 15 seconds. The sequence is reversed for shutdown, so the amps get turned off right away, then 15 seconds later the GK-1 gets shut down.  It's all very smooth and totally quiet.  The on/off sequence can also be triggered by power to a component (your preamp, for example) or by a DC trigger (3-30 volts, I believe).  I have the PF-60 buried in an "entertainment center" with little or no ventilation; the unit is barely warm to the touch after several hours of hard playing.

I've had the PF-60 for about a week now.  It has made turn on/off very easy (I want the family to use my system too), I have not noticed any deleterious sonic impact.  Since I am still working on getting the Orions dialed in, I will wait until things are stabilized and I have been listening for a while before I can give a definitive opinion (but to be honest, I have not heard large effects in the past from power cord changes or line filters).  The system sounds very, very good to me now, so it's unlikely that the PF-60 is doing a lot of sonic damage.

Peter

[CButterworth]

Peter,

My Belkin PF60 arrived yesterday.  I am still wondering how Ecost can sell a unit listed at $699 for $150.  Maybe the combination of silver faceplate and black chassis could be a clue.  I haven't plugged it in yet and will wait until my Amperite 10S delay arrives for my preamp.  This will allow 10S heating before switchong on B+.  I can set the Belkin to delay the rest of the system for 15S.  Also, if I understand the manual correctly, it'll switch off in reverse - main system, then preamp (of course heaters and B+ will be simultaneous).

I read some reviews and it seems that the sonic detriments of the Belkin were lower than Monster equivalent.  What I also like is the ability to handle surges and brown-outs.  We live on county land East of Phoenix, and during the summer monsoon storms, we frequently experience black-out, brown-outs and the like.  It is a real pain in the neck, but humorous - during the summer we had a 24H black-out during the fierce summer heat.  Then two days before Christmas, we had another long black-out, this time freezing fog frosted the power line and brought it down - we can't win   

Regards,
Charlie

[PSP]

Charlie,

Also, if I understand the manual correctly, it'll switch off in reverse - main system, then preamp...

Yup... that's the way it works.  Agreed, it's a very beefy and nice-looking component (looks and hefts much more like $699 than $160).  The surge protection is very welcome too... last year I had the 10R ground lift resistor on an AKSA 100N+ and one of the transistors on the GK-1 get blown in separate incidents.  The 100N+ was my brother-in-law's, plugged into a garden-variety surge protector.  The GK-1 was plugged into a Jon Risch line-filter/surge protector + the Jon Risch "super quick and dirty digital filter".  Now, I've got the whole system hooked into the PF-60; I think the system is safer, we'll see...

Peter

[CButterworth]

It all works brilliantly!  My $10 NOS Amperite 10 second delay arrived on Saturday.  I get no nasty bumps, thumps or hums.  A single switch turns everything on - smoothly.

It also seems that things sound just a little better than with my Monster power-strip.

After ordering from ECost, I read a bunch of postings about their terrible customer service on faulty items.  Maybe I was lucky, but what I bought worked.  I did open up the unit to check whether it looked similar to the insides of a photo published in a review - it did.  I also caught a rogue component leg sitting on the PCB.  I don't know how these items are made, but the legs must be clipped after soldering.  Anyway someone or something missed one in my unit.  A bit of careful fishing got it removed quite nicely.

Charlie