Rebuilt Quickie: "The Bonze"

[mcandmar]

Those labels i have not seen before, interesting. Also interested to hear how you get on with those as you own all of my favorite tubes, the Philips, Siemens, Telefunkens, Navy RCA's, and Mullards.

The Valvos are worth picking up too, and if you mod for 1S4 tubes try a few Czech 1L33's. They are horribly microphonic but i really like em, curious for somebody else to try them and see what they think.

http://bottlehead.com/smf/index.php?topic=6098.0

 

[Bonzo]

Ciao mcandmar,
I red your post and always thinking of doing the mod, but I'm too lazy...  ;D
I built also a sort of "quickie clone" changing tube's workpoint and something else, just to experiment a bit, maybe i can try the mod on it.

1L33 has also that "glow factor" I miss in the quickie... 

Speaking about tubes I think standard RCA's are a bit better than JAN ones, the latter being too much microphonic for my taste, now I have to do some more listenig session with the Tele's.

To reduce vibration I use also Mapleshade-inspired cork/rubber feet and I have to admit they do a good job for external vibrations.
I have also considered putting a rubber ring between tube socket and plastic plate.

Ciao!

 

[mcandmar]

You can do the mod via a toggle switch so its a quick and easy changeover.  Thats how i have mine setup, and another switch to move a few pins around so i could experiment with 3A4 and 3Q4 tubes too.

 

[aragorn723]

Mcandmar,

Have you noticed any significant differences from trying 3A4s and 3Q4s vs. the 3S4 in sound?

Dave

 

[mcandmar]

Mcandmar,

Have you noticed any significant differences from trying 3A4s and 3Q4s vs. the 3S4 in sound?

Dave

Cant really say as i only bought one set of each to experiment with and never did anything with them. The intention was to work out if any changes to their operating points were needed and modify accordingly. From memory one had higher gain which was useful, one has a higher power output, and there was also differences in trans conductance, distortion specs etc.  I wonder if the BH guys have tested them?

 

[aragorn723]

one interesting thing about the 3q4 is that you can get a pair of telefunkens on ebay for $20, vs. $35 for a 3s4 pair!

Dave

 

[mcandmar]

Spotted these recently that interest me, but i'm not paying $40 shipping for them :'(

http://www.ebay.com/itm/Vintage-Radio-TV-Philips-Miniwatt-Tube-Lot-Of-2-DL92-CT323-/181557526859?pt=Vintage_Electronics_R2&hash=item2a45ac014b

 

[Bonzo]

Just a thought: 3q4 seems a drop-in replacement to me, according to Radiomuseum.org:
This is our beloved 3s4 http://www.radiomuseum.org/tubes/tube_3s4.html
and this is 3q4 http://www.radiomuseum.org/tubes/tube_3q4.html

They seem pin to pin equal, is it correct?
Instead of a switch, have you tried to build a socket adaptor?

Ciao!

 

[mcandmar]

Yup that looks right, it was the 1S4/3A4 that had different pinouts. You could make adapters, though i dont know what you would start with.  I just found it easier and neater to add a few switches, easy to do when your dealing with such small voltages.

 

[Bonzo]

Mcandmar,
today I tried those beasts!

3Q5GT so HUGE with the adapter!  :

Size mismatch ;D

Nothing more than a quick check to see if everything works, but they seems pretty good!

 

[mcandmar]

He he.  Those look like an interesting tube from a quick scan of the datasheet, were they supposed to be an octal equivalent or the 3Q4?

 

[aragorn723]

Hi Bonzo,

How do you like the sound of the 3Q5GT tube compared to the 3S4?

Dave

 

[Bonzo]

He he.  Those look like an interesting tube from a quick scan of the datasheet, were they supposed to be an octal equivalent or the 3Q4?

It seems the equivalent tube is 1C5 (maybe 1C5GT is a bit better  ;D ), and they are really cheap on Ebay USA ($8 for a tested quartet!).
Only socket adapter was a bit expensive, but the little quickie is always worth every investment!

I also ordered a pair of 1L33 too, do you think that I can use them in the existing circuit by simply cutting pin n°1? As I told you I'm sooo lazy!  ;D ;D

 

[Bonzo]

How do you like the sound of the 3Q5GT tube compared to the 3S4?

Ciao Dave,
ATM I have no time for serious listening test...
From quick listen they seems promising: they are microphonics as usual but not too much, and they sound "correct", more like the Siemens.
The listening the setup was Apple ipod touch with lossless files>direct output from base pins>Quickie>Edcor transformers>AKG 141 (not so optimized...  ;D )

 

[Paul Joppa]

I'll just mention that there are a (small) number of tubes with 2.0v filaments, and that there exist 2-volt sealed lead-acid rechargeable D cells. Type 31 is especially attractive because its gain and plate resistance are close to the 3S4, and it's a real triode.

Finding a charger for the SLA cells will be more of a challenge.

 

[Bonzo]

Thank you Paul...
some more adapter to order (and even some SLA's  ;D )
Just to confirm your kit is an endless source of amusement, and your design is simly perfect!
THANK YOU! 

 

[mcandmar]

2nd that, i have learnt so much about valve amp design from PJ and the quickie, and i'm still not done experimenting.  It went from a preamp to a headphone amp, to an AC powered amp, and currently i am waiting for a few caps to finish my latest revision with a high voltage regulated power supply.  Still sounds great too!

 

[Bonzo]

Some updates: those big tubes are incredibly microphonic!!
I start suspecting that 3s4 is another design choice is better not to alter...  :

 

[aragorn723]

lol.  The funny thing with the Quickie is that it sounds really good with the pjccs (and there's probably no reason to mod it) but it is so tempting it's hard not to (plus the sound just gets better!)

Dave

 

[Paul Joppa]

People -  the Quickie deliberately follows in the footsteps of the original Foreplay, in being as much for fun and playing with as it is for listening to - it's just a fortunate side benefit that it actually sounds good. Rock on!