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"PQ" vs " SQ"?

Discussion in 'Tube Audio' started by Lavane, Dec 7, 2018 at 9:35 PM.

  1. Lavane

    Lavane AK Subscriber Subscriber

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    I bought a Amperex gold pin "PQ" E80CC to replace one that had one side short out. I also noticed an "SQ" version. Anyone know the difference between the special quality and the premium quality?
     
    Last edited: Dec 7, 2018 at 10:05 PM

     

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  2. primosounds

    primosounds Powered with pure tube sounds. Subscriber

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    I Never thought there was any difference. But i thought it meant tubes designed for 10K hours life span along with other manufacturing considerations depending on customer requirements.
     
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  3. gadget73

    gadget73 junk junkie Subscriber

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    one is "pretty quiet" the other is "super quiet"

    or I really have no idea.
     
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  4. Lavane

    Lavane AK Subscriber Subscriber

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    I did find info on both that claimed 10K life. And looking at pictures of both with round getters and gold pins they looked the same. It's my favorite center position signal tube in my ST-70. The difference between an old stock e80cc and a 12au7 is very noticeable.
     
  5. Lavane

    Lavane AK Subscriber Subscriber

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    They both claim very quiet, rugged, long life, etc. Eh, who knows.
     
  6. mhardy6647

    mhardy6647 AK Subscriber Subscriber

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    Thus the rare and über-expensive "FQ" series.

    :cool:
     
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  7. primosounds

    primosounds Powered with pure tube sounds. Subscriber

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    It maybe PQ is an Amperex trademark. There was a time when the tube makers decided to have special tubes for critical applications. GE "5 star", RCA "Command", Sylvania "Gold brand", Mullard 10M. But i can't recall which maker uses SQ, it might be Amperex , too.
     
  8. Lavane

    Lavane AK Subscriber Subscriber

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    Ya, I found both on Amprex branded tubes. Made by Philips, I tnink. Tunsgram was the other manufacturer of the e80cc originally. Then rebranded by others like Valvo, etc.
     
  9. arts

    arts Super Member

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    Considering how bad every one of these that I have found is ( used or NOS) I came to the conclusion that PQ is Pitiful Quality and that SQ is Shi**y Quality.
    Just my own experiences of a few dozens of these types,and I just don't get the hype OR the price:dunno:

    My recommendation: Test before buying.
     
  10. Lavane

    Lavane AK Subscriber Subscriber

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    Both I've bought were tested and triode matched. The first one I paid very little for. I agree they have shot way up in price. But for whatever reason, they just sound right to me in my st70 with 12bh7's on each side. Some really like the 12bh7 in the center, but they sound a bit thin to me.
    We're you using them in a guitar amp?
     
  11. Selmerdave

    Selmerdave Well-Known Member

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    I've always found PQs to be excellent-sounding tubes.
     

     

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  12. arts

    arts Super Member

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    No,I most certainly was not using them in a guitar amp.They were either being used in industrial applications or test equipment.And of the ones I have tried using in audio applications,most were noisy and/or microphonic.As to what they ''sound'' like,I don't play that game;)
     
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  13. sKiZo

    sKiZo Hates received: 8642 Subscriber

    Maybe their way of sorting the production based on final tests before packaging. Lots of ways that was done. Fer instance, "stars" were the cream, and these were both low microphonic AND medical grade as well, shown by the paint daubs on the tops.

    [​IMG]
     
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  14. gadget73

    gadget73 junk junkie Subscriber

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    how about the RFQ ?
     
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  15. Retrovert

    Retrovert AK Subscriber Subscriber

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    The difference is marketing.

    No practical difference exists between PQ and SQ:
    Amperex PQ = Premium Quality
    Philips SQ = Special Quality
    So this is the same tube, just different marketing nomenclature for Europe vs. USA. In the US "special" wasn't as powerful a term as "PREMIUM".

    The PQ/SQ tubes were designed and manufactured to better standards than ordinary tubes: more rigid supports to be less microphonic and extend lifespan; better getters to reduce gas, increase performance, and extend lifespan; better heater construction to reduce hum and extend the filament's lifespan; and a more expensive internal construction, including the spacers. Well, it's complicated than this, as Philips tended to rebrand tubes, as did Amperex, so the tubes might have been made by an entirely different vendor. (shrug)

    I have a handful of PQ tubes in a 1960s reel-to-reel I was gifted. (Most of those R2Rs are stripped for the PQ tubes and then the rest of the unit is discarded.) It makes sense that in a vibration-prone environment such tubes would have greater benefit. But for typical audio use? Probably no difference from any other tube in its class. The demand is likely just the mystique of using a "premium" or "special" tube.
     
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  16. Lavane

    Lavane AK Subscriber Subscriber

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    Thanks! That explains it. I noticed the Amperex were acually Philip's when doing my search. The first one I had was a Tunsgram branded Siemens with a D better. This one is a bit taller with a halo better at the top and gold pins.
     

     

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  17. gadget73

    gadget73 junk junkie Subscriber

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    Phillips couldn't sell under their own name in the US because it was too similar sounding to Philco. Or so I've heard at least. They bought out Amperex for the name, but they also sold things under the Norelco brand. Maybe they didn't want to associate tubes and electric razors though.
     
  18. Chrisxo55441

    Chrisxo55441 AK Subscriber Subscriber

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    i like my PQ's better then my SQ's mostly because i paid more the PQ's and it makes feel better about spending more on them
     
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  19. Retrovert

    Retrovert AK Subscriber Subscriber

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    Yeah, I've seen those claims, but not only are they incorrect, the explanation totally defies trademark law and basic marketing. The claims are dead wrong. Philips did sell in the US under its own name, but many good reasons existed for the Amperex acquisition and maintaining it as a separate brand.

    Philips was a conglomerate and had many, many brands under its roof. It was like GE or RCA. Amperex was a long-standing manufacturer of signal tubes, but it was the Amperex's substantial patent portfolio and the transmitting tube business which delivered the true acquisition value for Philips. Remember, this was 1955 so the tube business was really taking off.

    The war had seriously damaged or destroyed European manufacturer's R&D efforts and manufacturing capability, while it had boosted those in the USA, dumping in vast quantities of money. While this was ten years later, the American manufacturers had a serious head start. So Amperex was a very advanced competitor. Don't forget that the Philips plants had been bombed during WWII because the Nazis were using the tubes for the Wehrmacht. All of the German plants had been looted by the Soviets, crated up and shipped back home. (Those facilities were civilian property and stealing them was a war crime. But that's just a side issue not, well, germane to the value of acquiring Amperex.)

    It was easy for Philips, as it is for many large foreign companies, to gobble up a smaller company, acquire the considerable patent portfolio, evade tariff and trade restrictions, eliminate shipping costs by performing domestic manufacture, obtain economies of scale, obtain new designs, all while removing a competitor. What's not to like from monopolistic behavior, unless one is a consumer?
     
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  20. Retrovert

    Retrovert AK Subscriber Subscriber

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    The "premium" products always beats the lowly "superior" one.
     
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