Search found 59 matches
- Tue Jun 07, 2005 1:12 pm
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
Hi again Jarek, at 90mA gm is stated to be 5, mu 25. I don't have transfer curves to predict what it might be at my operating point. It has the benefit of the extra dissipation 350w if used below 100mcs with ambient cooling conditional upon really good heat sinking connectors, particularly anode. It...
- Tue Jun 07, 2005 10:32 am
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
I could have discussed this in that secret place where you get hit by the mob if you tell anyone it exists, but I know Steve and Dave, key witnesses lurk here, it seems you too, so we have a quorum. This is a public place afaik. Anyone that isn't visiting is missing out, and quite honestly isn't mis...
- Tue Jun 07, 2005 10:04 am
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
What Vry means is that because you are only inetrested in tweeter frequencies the air cap coupling inside the amp (or perhaps a pair) has sufficient pass point. You can of course tune if you get air variable caps. Maybe a vacuum cap and an air variable in parallel if more required than is available ...
- Tue Jun 07, 2005 6:12 am
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
Good day Steve, I think I'll go dual mono so that I'm not shuntiung so much current. I could then use one 572b within it's ratings at say 100mA for the first stage of filtering and then use the ty4-400 for the second stage to shunt 200mA. The output stage would probably run at 130mA, the other stage...
- Mon Jun 06, 2005 10:18 pm
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
- Mon Jun 06, 2005 10:12 pm
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
- Mon Jun 06, 2005 10:01 pm
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
I have to say it's a big mistake phoning Vry because when you eventually get off the phone your head is full of all sorts of ideas thrown out by a mathematician. I only just ordered at great expense Mundorf Silver Golds to hopefully be the final tweak for the Ariels and Vry is telling me to build a ...
- Mon Jun 06, 2005 9:54 pm
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
Yes, I just spent all evening on phone to Vry, he put me right off the prefix series reg idea, though I do have some 13e1's which could do it. Like you say rdc is not a problem at all. Did I say how good the capless supply is in the driver part? Recovery from transients is instant, gives the impress...
- Mon Jun 06, 2005 6:20 pm
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
Jarek thanks for coming in. I have already built the supply for the px25 part using two stages of 572b and compared to solen caps it's a revelation. Thanks for the tips on using vr's. I'd better look out for those higher voltage ones then. I didn't however have a problem getting the 20 75/60's to li...
- Mon Jun 06, 2005 7:07 am
- Forum: Pb Place
- Topic: Yorkshire Boatanchor event
- Replies: 28
- Views: 37119
Yorkshire Boatanchor event
The event was a resounding success. I'll be linking a web page for it when built. I'd like to use my area here to discuss with Steve Bench and you dave where to go from here in development of my 212 power supply. On the face of it that may seem a stupid question. I used Steve's resistorless capacito...
- Thu Apr 21, 2005 5:13 pm
- Forum: Transformers
- Topic: Bass only SE OPT on AMCC1000...
- Replies: 15
- Views: 14405
- Thu Apr 21, 2005 6:37 am
- Forum: Transformers
- Topic: Bass only SE OPT on AMCC1000...
- Replies: 15
- Views: 14405
Ahh, I've just realised who you are Shinebox. That sound on your Martin Logans was excellent, but yes we were driving those poor 4212's at the top of their ability and still the panels wanted more. We were getting compression. I think you are mad though with all your ideas, but the occasional phone ...
- Wed Apr 13, 2005 11:50 am
- Forum: Transformers
- Topic: Push-Pull transformers and gaps.
- Replies: 19
- Views: 22591
- Wed Apr 06, 2005 11:47 am
- Forum: Transformers
- Topic: 1:1 bifilar output to remove the parafeed coupling cap.
- Replies: 31
- Views: 37037
I can't promise anything James but just might have an 833 output stage in one of these forms for June. Trouble is I have a so much day job work to do, time is at a premium. I do have the 2kv power supply that could handle the current though. However a 300ma ccs is a bit of a task, is that an easy jo...
- Wed Apr 06, 2005 7:19 am
- Forum: Transformers
- Topic: 1:1 bifilar output to remove the parafeed coupling cap.
- Replies: 31
- Views: 37037
- Wed Apr 06, 2005 6:53 am
- Forum: Transformers
- Topic: 1:1 bifilar output to remove the parafeed coupling cap.
- Replies: 31
- Views: 37037
Dave, thinking on similar but different lines for higher voltages. I want to try an 833a output instead of my 212. The JAmes Transformers are just 40 watt rated at 130mA dc I think. I was planning to parafeed so that the 200 to 300 mA dc current didn't have to be handled by the OPT. I would also con...
- Tue Mar 29, 2005 6:40 pm
- Forum: Transformers
- Topic: How come transformers sound so good?
- Replies: 5
- Views: 7100
- Mon Mar 28, 2005 7:29 pm
- Forum: Transformers
- Topic: How come transformers sound so good?
- Replies: 5
- Views: 7100
- Mon Mar 28, 2005 1:38 pm
- Forum: Transformers
- Topic: How come transformers sound so good?
- Replies: 5
- Views: 7100
How come transformers sound so good?
Just wound a pair of interstages out of EI120. That is the back of the E is 120mm the rest follows scrapless dimensions. Fairly much the same as an imperial 120. There are 4 sections per side of 1180 turns 0.212mm wire which is six passes per section. I've connected series parallel on the input to g...
- Sat Mar 26, 2005 10:42 am
- Forum: Transformers
- Topic: a new Bridged cap IT
- Replies: 4
- Views: 4946
- Mon Mar 21, 2005 1:11 pm
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
Sorry guys I have completyely lost interest in this tranbsformer. It isn't big enough for my needs. The source of bonded bifilar is too expensive for me to go any further. New question, how is the dialectric tension between two single strand wires wound together? Shall I try that next? What do you t...
- Sun Mar 20, 2005 9:06 am
- Forum: Transformers
- Topic: a new Bridged cap IT
- Replies: 4
- Views: 4946
Just a bit of parallel thinking. What if you had some cheap 1:1 transformers available to you, but instead of passing hf with a cap, you used a pair or more of these transformers in series (with the obvious benefit of being able to parallel or series the windings to arrive at required ratio), in the...
- Sun Mar 06, 2005 9:41 am
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
OK maybe now it has to be time for listening. That might take a little longer. Don't forget no gap doesn't exist it's but gap in slab stacked lams isn't it? There is maybe more dc protection in that construction at 13ma than you are allowing for. The dc current figures are calculated from the ccs fo...
- Sat Mar 05, 2005 12:11 pm
- Forum: Your name here.
- Topic: 304tl project
- Replies: 2
- Views: 6712
- Sat Mar 05, 2005 9:33 am
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
- Fri Mar 04, 2005 9:04 pm
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
Hi again Dave et al OK I did a little work 4 8 0 0.027 89 0.068 35 1 0.07 34 0.09 26 2 0.105 23 0.125 19 3 0.143 16.85 0.152 16 The chart hasn't copied brilliantly 4 and 8 are milliamps dc 0,1,2,3, are numbers of post it notes ac voltage in at 50hz in each case was 5.35 volts Cap size 22.5 uF 0.027 ...
- Thu Mar 03, 2005 8:30 am
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
Thanks Dave, I expect the lams are scrapless. In any case the dimensions are roughly. Central protrusion of E 25mm Each outer limb 25mm Back of E 75mm with 40mm stack. I'll do the further testing in a matter of days. The output of the sig gen is severely suspect and the Fluke 87 may not be reading c...
- Wed Mar 02, 2005 10:35 pm
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
Can someone check my maths, in the past this was easy for me, but I've been out of it for a few years. Just wound a 40mm st6ack of EI 75 ( back of E is 75mm long) M6 sil. Managed 3,277 turns. Put 18ma ccs on one winding and injected 10hz into other 4.29v rms measured at input, 22uF cap at output 0.9...
- Mon Feb 21, 2005 9:02 pm
- Forum: Transformers
- Topic: Using Bifilar Wire
- Replies: 20
- Views: 17623
I also take my wire off the top of the spool and then pass it through a felt guide and a wheel. I also have to hold it between thumb and fingers to better tension it. I find that if you go too fast when taking wire off the top it whips itself into a knot. I believe cone shaped cover with a hole in t...