Lampizator Valve / Tube Rolling Review Thread

[Tuckia]

Yes, I meant rectifiers and not drivers obviously.
So KR 5U4GRK is the Holy Grail here? Need to give it a try. Thanks for the hint.

I have both regular and RK versions of the KR 5u4g. The RK is more refined. Given the higher burn rate (shorter lifespan) of the rectifiers in Lampi’s compared to the outputs, I’m adverse to using rare, high cost NOS rectifiers for daily use. But NOS are definitely worth pursuing.

 

[JSA]

No, it is not the holy grail but you may like it more than other tubes. There is no holy grail since every driver tube matches differently with different rectifiers.

Thanks, when it comes to driver tubes I have tried a lot from KR, EML, Elrog and some Chinese tubes. In my GG2 clear winner is KR 242, and KR242RK is the 2nd choice. It seems I need to experiment more with rectifiers.

 

[JSA]

I have both regular and RK versions of the KR 5u4g. The RK is more refined. Given the higher burn rate (shorter lifespan) of the rectifiers in Lampi’s compared to the outputs, I’m adverse to using rare, high cost NOS rectifiers for daily use. But NOS are definitely worth pursuing.

What is the typical lifespan of rectifiers in Lampi?

 

[Tuckia]

What is the typical lifespan of rectifiers in Lampi?

I see no one has taken a stab at this yet. I'd venture a guess of 20-30% of the life span of the output tubes. Maybe 2-3 years vs. 10 years. I do not have a tube tester to support this answer. Hopefully someone can add to this. The rectifiers run much hotter than the outputs - about 50F. Full throttle (or, no throttle?). Is a Lampi carbureted or direct injected?

 

[Jazzhead]

A friend of mine uses T100 in his Pacific. Supposedly that is the Holy Grail to go for.
In my GG2 I prefer KR242 over PX25 big time.
Another friend of mine uses FullMusic PX25 with great results in his GG1. In his case EML45 is also a great choice and alternative to PX25.

Any idea how he uses the T100.... I am told the base is too thick for the PAC cut out, .... Adapters?

 

[Zero000]

Any idea how he uses the T100.... I am told the base is too thick for the PAC cut out, .... Adapters?

Just unscrew the lid. Not great, but it'll work.

Or use socket life extenders.

 

[highstream]

I see no one has taken a stab at this yet. I'd venture a guess of 20-30% of the life span of the output tubes. Maybe 2-3 years vs. 10 years. I do not have a tube tester to support this answer. Hopefully someone can add to this. The rectifiers run much hotter than the outputs - about 50F. Full throttle (or, no throttle?). Is a Lampi carbureted or direct injected?

First, I don’t have the experience yet to know. I’ve read estimates like yours, but ran across someone on a forum discussion seemingly knowledgeable who claimed rectis outlast output tubes.

 

[Tuckia]

First, I don’t have the experience yet to know. I’ve read estimates like yours, but ran across someone on a forum discussion seemingly knowledgeable who claimed rectis outlast output tubes.

This could be the case for some power amps, like my Allnic's which run 5u4g. Most comments I've read about Lampi's fall inline with my comment.

I had run my RK 5u4g almost exclusively for close to two years and it seems to be sagging now. My RK PX25 are almost as old (one of the first pairs in the wild) and seemed to be doing fine. I'd like to test them, but haven't done so yet. I'm not running any of these recently so for now the clock has stopped.

Did this poster cite which Lampi model and measurements? Others here must have done this already. But swapping daily makes clock watching difficult. Anyone running a spreadsheet logging the minutes? I don't have that kind of OCD.

 

[christoph]

I had run my RK 5u4g almost exclusively for close to two years and it seems to be sagging now.

I have a spare brand spanking new RK 5u4g to compare back my workhorse RK 5u4g to should I sense some form of detoriation

 

[Tuckia]

Thanks Christoph. For grins I've dropped my RK into one of my amps, replacing a newer KR 5u4g. These amps have bias current meters on the outputs. Just looking for clues on behavior. The RK did take noticeably longer to come up to full, stable bias - 10 minutes vs. 1 minute. But it did come all the way up. I have a buddy who has been selling Tubes World wide for a few decades. I may just take a trip over to get the lot tested. Will revert back.

 

[highstream]

It would be interesting to hear what you buddy has to say about the signs of a dying tube, short of the sound stopping, that is, measurements aside, which most of us don't have access to.

 

[christoph]

Thanks Christoph. For grins I've dropped my RK into one of my amps, replacing a newer KR 5u4g. These amps have bias current meters on the outputs. Just looking for clues on behavior. The RK did take noticeably longer to come up to full, stable bias - 10 minutes vs. 1 minute. But it did come all the way up. I have a buddy who has been selling Tubes World wide for a few decades. I may just take a trip over to get the lot tested. Will revert back.

Thanks for the precious info.
Did the change of rectifier in your amp make a sonic difference as it does in the Lampi DACs?
IME the RK recti sounds quite a bit better than the KR 5u4g

 

[JSA]

Any idea how he uses the T100.... I am told the base is too thick for the PAC cut out, .... Adapters?

in my friend’s Pacific, T100 are mounted via adapter.

 

[JSA]

Regarding rectifiers in Lampi I have done some direct comaprison in my GG2 (output tubes Kr242).
My observations: KR5U4G and KR274B are essentially the same in my system. If there are differences then really subtle and almost beyond perception.
ACME Psvane 274B is in my setup significantly better: much more resolution, bigger soundstage. The only drawback is that ACME is very warm in sound signature, so in some cases I can imagine some people might prefer KR recti.
It is most evident in the bass range where both tubes go deep, acme more tuneful and more colofrul - however KR and ACME give different sonic signature.
All in all not bad to have KR and ACME and swap sometimes depending on he mood.

 

[Tuckia]

It would be interesting to hear what you buddy has to say about the signs of a dying tube, short of the sound stopping, that is, measurements aside, which most of us don't have access to.

I’m trying to get a play date set up with him. Could be 2 to 3 weeks depending on how the Packers do

Rectifiers tend to die a slow, gradual death. This makes it hard to pick up. Front to back I’ve 22 tubes in my system, so it’s like managing 22 slowly dying souls. However, my RK is by far the oldest of the lot. Currently I’m not running any of my RK’s, instead a Japanese U52 from the early 60’s and Shuguang Black Treasure 300b’s, which are newer and working nicely.

 

[Tuckia]

Thanks for the precious info.
Did the change of rectifier in your amp make a sonic difference as it does in the Lampi DACs?
IME the RK recti sounds quite a bit better than the KR 5u4g

Well, the amps are dual mono, so one had the RK; the other a regular KR. So the effect is diluted. Also, the effect is lessened in the amp position compared to the dac, as you would expect. Sure, the RK is better in the amp in the same ways - better detail, more refined, and a grander presentation through the lower mid-range.

With old stock tubes escalating with every post here (it seems) the RK 5u4g is now a better value than before, if it suits your system. I look for linearity and resolution in my tubes (because the system has so many). Not trying to soften or add effect. This is where the KR tubes do well in a modern hi-res world. If I want soft and forgiving, I plug in my old GEC U52 and UX112a outputs.

Unfortunately for US, the USD exchange rate sucks right now.

 

[Golum]

With old stock tubes escalating with every post here (it seems)...

Almost can't find any of the 12/112A anymore :-(

 

[dminches]

Almost can't find any of the 12/112A anymore :-(

You bought them all!

 

[Tuckia]

At my suspected burn rate, I'll need about (66) PX25 and (45) RK 5u4g to make it to the end of days. Time to start hoarding.

Fortunately these tubes are total rubbish and will start to appear on ebay for little or nothing. The UF4 base are a particularly foul lot.

 

[Golum]

You bought them all!

Actually i didn’t - have like 4/5 pairs maybe and out of that i got like 3 pairs with my pre...