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Ordered a Schiit Aegir (single) for my Cornwalls....


costerdock

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2 minutes ago, costerdock said:

It is awesome that you liked the Aegir so much that you got another - that is a great indication to me that these are nice amps.

To be perfectly honest I liked the amp enough to experiment with two; hoping to find that elusive audio nirvana eluding me with my current setup: one Aegir and two Vidars.

I can't avoid the suspicion that I have made myself the victim of unrealistic expectations. But, I think of an old Walter Egan line: "and the joy is in the chase" - (Just The Wanting) by Walter Egan on Not Shy. You may find that the Aegir does it for you. It seems to work for a lot of listeners; some on this forum. Good luck! I wish you the best.

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19 hours ago, costerdock said:

I'm doing this because - my amps have killed enough tubes and people that seem to know what they are talking about (VTA folks - Bob, Roy) - non VTA folks - all say - you can't run the SS WS1 w/o a time delay module.

 

As a consumer I have to listen to what I feel are experts - not to mention my own experiences with these amps blowing rectifiers, and output tubes - I'll do anything to take it easy on those tubes.

 

I told you why the amps are rough on power tubes, there are 500v on the screens of the power tubes, high voltage UL amps like this are very rough on current production tubes.

 

The time delay is there not for cathode stripping but because they designed the voltage rating for the power supply for operating voltages under load and not for maximum unloaded power supply voltages. The fast ramp up of voltage before the tubes warm up and load the power supply down stresses the capacitors not the tubes.

 

You can believe "the experts", I'll still sleep fine at night.

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18 hours ago, Curious_George said:

Yep, Cathode Stripping, biggest urban myth there ever was and people are still defending it today on the Internet. 

 

I am pretty certain 500v on the screens with current production tubes is a much bigger issue vs non existent cathode stripping but hey what do I know, I'm not an "expert". It's fine because over time he'll still find the amp is eating through power tubes with the time delay board.

 

The reason for the time delay board is because the power supply was designed for working voltages and a slow ramp up 5ar4 rectifier, the SS rectifier puts stress on the power supply capacitors not the tubes. Hmm bad power supply capacitors, I wonder why his failed so soon? Must have been the cathode stripping that killed the caps🙃

 

 

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31 minutes ago, captainbeefheart said:

 

I told you why the amps are rough on power tubes, there are 500v on the screens of the power tubes, high voltage UL amps like this are very rough on current production tubes.

 

The time delay is there not for cathode stripping but because they designed the voltage rating for the power supply for operating voltages under load and not for maximum unloaded power supply voltages. The fast ramp up of voltage before the tubes warm up and load the power supply down stresses the capacitors not the tubes.

 

You can believe "the experts", I'll still sleep fine at night.

 

So what is your point - I don't need the slow ramp up?  It won't help?  It will help the caps?  I don't recall bringing up cathode stripping - so not sure where that topic came from.

 

I'm going to bring the amp in to a local tech to have checked out - I'll see what their assessment is.

 

I'm not trying to be argumentative - this is not my wheelhouse - so I have to consolidate all the advice and determine a reasonable path.

 

I think the tech first - then I can report back on their findings and get better direction.

 

Thanks

 

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On 3/10/2022 at 1:15 PM, costerdock said:

The only one to run SS is the WS1 - but that requires a slow tube warmup module - otherwise the voltage will come on too fast and hurt the tubes. 

 

The warmup module isn't for the power tubes, it's so the power supply capacitors don't get stressed during power on with SS rectifiers.

 

13 minutes ago, costerdock said:

So what is your point - I don't need the slow ramp up?  It won't help?  It will help the caps?  I don't recall bringing up cathode stripping - so not sure where that topic came from.

 

You will need it so you don't damage the power supply capacitors during power up with SS rectifier.

 

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Although it's still tough on the tubes vintage KT88's wouldn't get destroyed from the high screen voltages in UL mode but modern production KT88's might not be a true KT88, just something else close to it and labeled KT88 for broader sales.

 

The EH KT90 is a tube that I have found take the abuse well in these types of amps much better than many so called "KT88's" being offered. Either that or run NOS tube but that would be very expensive.

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8 minutes ago, captainbeefheart said:

Although it's still tough on the tubes vintage KT88's wouldn't get destroyed from the high screen voltages in UL mode but modern production KT88's might not be a true KT88, just something else close to it and labeled KT88 for broader sales.

 

The EH KT90 is a tube that I have found take the abuse well in these types of amps much better than many so called "KT88's" being offered. Either that or run NOS tube but that would be very expensive.

 

Thanks.  I think as a consumer - I found the Rubli delay board a reasonable solution - however I did not know I was dipping my toes into a controversial subject 'Cathode Stripping' which that board solves.

 

I was hoping to try these cheap chinese Kt88s:

 

https://www.ebay.com/itm/183711711760

 

Some have reported they work well.

 

All I know is the Gold Lions I buy haven't lasted very long.  Perhaps I should just jump to the KT120s.

 

First things first.  I'll get it to a tech and report back.

 

Thanks again - have a wonderful weekend!!!

 

Chris

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Besides the abuse of the screens in these amps I forgot to mention that the plates can swing to near 2x B+ voltage, yes that's 1kV on the plates, sockets, wiring and output transformers. These amps need really high quality and robust power tubes for a decent lifespan, it's just the nature of the beast. Instead of copying old designs Bob should have just thrown ultralinear out the window with these amps and just ran pentode operation with a much lower screen supply. The amps would be much more tube friendly and reliable.

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1 minute ago, costerdock said:

however I did not know I was dipping my toes into a controversial subject 'Cathode Stripping' which that board solves.

 

It's not really controversial to people that understand how tubes function. The board doesn't solve cathode stripping because it's non-existent, it's to band-aid a poor power supply design with too low voltage rating to handle a SS rectifier. Bob isn't going to go and admit openly his original power supply design is barely adequate for the circuit, as I said it's designed for working voltages not no load voltages which is corner cutting. That amp should have at least a 700vdc rating.

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33 minutes ago, costerdock said:

Man that cheap ebay quad - those are some fugly tubes - with the gold bases.  

 

6550's will be worse in those amps. That's the issue, most of the KT88 tubes being sold are closer to a 6550 which is why they don't tolerate those amps very well.

 

The KT120 has the same screen specs as the KT90, Ultra linear rated screen voltage of 600v and 8 watts dissipation. The 6550's and most KT88's won't like more than 400v on the screen.

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2 hours ago, captainbeefheart said:

Hmm bad power supply capacitors, I wonder why his failed so soon? Must have been the cathode stripping that killed the caps🙃

If the brand of capacitor is not known, it could be a crummy Chinese cap. I'm not openly disparaging the Chinese, but they are well known to release inferior products that do not last, especially capacitors. 

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56 minutes ago, Curious_George said:

If the brand of capacitor is not known, it could be a crummy Chinese cap. I'm not openly disparaging the Chinese, but they are well known to release inferior products that do not last, especially capacitors. 

Bob uses good quality components - I know the few caps I did replace were all CDE.  I've never read any complaints about the quality of the kit parts - that is for sure. 

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1 hour ago, costerdock said:

Bob uses good quality components - I know the few caps I did replace were all CDE.  I've never read any complaints about the quality of the kit parts - that is for sure. 

 

He uses the multi-section can capacitors which are notoriously known to be garbage, they have a high failure rate which is why I refuse to use them in anything anymore. These are mainly the CE manufacturer types, I have had decent luck with some labeled "Hayseed Hamfest" or something like that.

 

It's not worth the vintage look of the can style caps, or if you absolutely need to have it for restoration I'll gut the old one and stuff with high quality modern types. The modern radial electrolytic caps from the reputable big brands are inexpensive and vastly superior, it's best to design the amp around them vs an outdated vintage style can look. Bob Latino should know this and have a power supply board for these amps designed to take advantage of high quality inexpensive power supply capacitors. Those can style caps are like $60each, that's insane when $15 worth of Nichicon's would be a far better choice.

 

 

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9 minutes ago, captainbeefheart said:

 

He uses the multi-section can capacitors which are notoriously known to be garbage, they have a high failure rate which is why I refuse to use them in anything anymore. These are mainly the CE manufacturer types, I have had decent luck with some labeled "Hayseed Hamfest" or something like that.

 

It's not worth the vintage look of the can style caps, or if you absolutely need to have it for restoration I'll gut the old one and stuff with high quality modern types. The modern radial electrolytic caps from the reputable big brands are inexpensive and vastly superior, it's best to design the amp around them vs an outdated vintage style can look. Bob Latino should know this and have a power supply board for these amps designed to take advantage of high quality inexpensive power supply capacitors. Those can style caps are like $60each, that's insane when $15 worth of Nichicon's would be a far better choice.

 

 

They are German made Authenticaps - I haven't heard of to many complaints as I've been following these amps for a while.

 

But probably would be good to get rid of it and replace it with something more robust - I'm all for that.

 

Thanks.

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They use Authenticap multi-sections which are maybe a little better than CE, I did find the datasheet and it states 8% loss angle which isn't great. Typical Nichicon general purpose will be 2% or less. What's this mean? Higher losses and more heat built up inside the capacitor killing it faster.

 

EDIT: I just saw you posted them being authenticap which is correct. I would feel better with them over CE for sure.

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Wow - just wow - really loving this new little amp.   Just setup yesterday and listened to one album side - Joe Henderson's State of the Tenor - Vol 2 (side 1) - a favorite.   Great everything and the noise floor is reduced - in the 20's dB from a simple iPhone dB app (my tube amps from a recent test - no ground lifts - was in the 30's.)

 

Great first impression for sure.

 

 

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