|Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
||Thread Tools||Search this Thread|
|4th March 2012, 07:35 PM||#1|
Join Date: Aug 2005
OPT choice for PP1C
I am still working on my PP1C, see:
Rundmaus at work - PP1C without sand - diyAudio
Now, here's another question to the diyaudio community, concerning the choice of output transformer:
The schematic suggests a 5k plate-to-plate transformer, and at first sight I thought a Lundahl LL1663 5k:8 Ohms would do. But with the winding ratio of 24:1 given in the Lundahl datasheet, this is merely 4.6k:8 - with the ratio being even worse when impedance variations (usually downwards) of the speakers are taken into account.
What do you think, is 4.6k:8 acceptable with the usual impedance variation 8 Ohm speakers produce?
Alternatively, one could use the LL1620, LL1623 with primary impedances of 5-6k, but the LL1663 is already 130 Euros and the larger ones are close to 200 Euros per piece. This is getting too expensive!
Alternatively, I have a transformer vendor who could custom-wind C-core output transformers - stock values are 6.6k:8 but different ratios are doable on request.
So the choices are:
1) Take the cheaper Lundahls and live with 4.6k:8 or worse.
2) Pay a lot of money for the multi-impedance Lundahls.
3) Get a custom-wound C-core OPT for half the price of the Lundahls, but with no experiences concerning quality. The power transformer bought there was very nice, but OPTs and their winding techniques are a different beast....
What do you think?
|4th March 2012, 07:52 PM||#2|
Join Date: Sep 2009
Location: Aarhus, Denmark
Allen recommended the LL1663/PP over other Lundahl OPTs. Allen claimed the Lundahl OPTs to better than Tamura.
I use the LL1663 myself and I'm most satiesfied.
Get'em all tell us your findings... ;-)
Manufacturers and dealers produce and sells what sells
|Thread Tools||Search this Thread|
|Thread||Thread Starter||Forum||Replies||Last Post|
|Rundmaus at work - PP1C without sand||Rundmaus||Tubes / Valves||24||8th October 2012 06:27 PM|
|More Questions about A.Wrights PP1C||Rundmaus||Tubes / Valves||5||24th February 2012 05:10 PM|
|Power supply for PP1C - sanity check||Rundmaus||Tubes / Valves||7||16th December 2010 07:14 PM|
|Source for OPT||CarlyBoy||Tubes / Valves||6||13th March 2008 03:48 AM|
|Choice of a sub||elizard||Subwoofers||4||13th December 2003 07:32 PM|
|New To Site?||Need Help?|