Search found 29 matches
- Thu Sep 08, 2011 12:30 pm
- Forum: Transformers
- Topic: 4212 Output transformers
- Replies: 0
- Views: 3743
4212 Output transformers
Hi Dave. I think I mentioned this to you before, but I am in the market for a pair of beefy output tramsformers. Output valve STC 4212 and friends. B+ 1500v Max current 160ma. Maybe looking at 80W at 25Hz as a target. I think 7k looks like a good starting point, and there will be 6A DC available via...
- Sun Jun 19, 2011 7:28 pm
- Forum: Pb Place
- Topic: Partial Choke Loading of Cathode Follower
- Replies: 13
- Views: 17422
This is the source of the idea behind the driver stage http://www.jrossmacdonald.com/jrmpubs/040CathodeFollower.pdf In the scope picture, the center line of the display as the 0v line, idle bias was about -7v, I think we were looking at 60v P/P, going 25v into A2, the limit on volume was the loudspe...
- Thu Jun 09, 2011 1:02 am
- Forum: Pb Place
- Topic: Partial Choke Loading of Cathode Follower
- Replies: 13
- Views: 17422
- Tue Jun 10, 2008 9:25 pm
- Forum: Transformers
- Topic: Another DAC question, TDA1541 this time.
- Replies: 14
- Views: 13657
- Mon Jun 09, 2008 6:56 pm
- Forum: Transformers
- Topic: Another DAC question, TDA1541 this time.
- Replies: 14
- Views: 13657
Re: The SUT Graphs Look So Good...
... that I am tempted to try another DAC. Anybody has a spare CPLD? Properly done SUT peaking could take care of most of the sinx/x correction and some of the roll-off above 20kHz. Regards, TonyB PS: Do not forget to re-clock signals after the CPLD. I must admit to not fully understanding what you ...
- Tue Jun 03, 2008 6:26 pm
- Forum: Transformers
- Topic: Another DAC question, TDA1541 this time.
- Replies: 14
- Views: 13657
- Tue Jun 03, 2008 12:50 pm
- Forum: Transformers
- Topic: Another DAC question, TDA1541 this time.
- Replies: 14
- Views: 13657
Looks hopefull, I tried to get somewhere near the #3 setup, but using a pair of 1:10 MC setups I had on hand. It works, and sounds better than I expected, so its certainly got promise. I think I can hear the fact that the step ups are being driven about 40dB harder than they were designed for. So Da...
- Sat May 31, 2008 6:43 pm
- Forum: Transformers
- Topic: Another DAC question, TDA1541 this time.
- Replies: 14
- Views: 13657
That response is doing half the work for us :-). I was thinking in the order of 1:10, so 1:7 is fine, takes it to the point where something like an aikido can be used to drive the output. I3 looks good, the step up might need to handle a little DC, the DAC's idle current varies a little, I have seen...
- Tue May 20, 2008 1:55 pm
- Forum: Transformers
- Topic: Another DAC question, TDA1541 this time.
- Replies: 14
- Views: 13657
Another DAC question, TDA1541 this time.
Hi Dave, Myself and another couple of the usual suspects (Andrew and Tony) have been looking at creating a new DAC between us. Having heard and decided we prefer the TDA1541 we want (for the moment) to go with that one. There are a couple of additional features involved like interfacing to a squeeze...
- Wed Jun 20, 2007 6:47 am
- Forum: Your name here.
- Topic: more pics
- Replies: 36
- Views: 79563
I must admit both of the previous (interesting) graphs are why I have been spending a lot of time building and listening to amps with various regulated supplies. Have you tried the same sort of thing but with a two stage filter? I found it very hard to convince myself that the variations of impedenc...
- Sat Feb 10, 2007 12:47 pm
- Forum: Phono
- Topic: IT loaded pentode to feed a LCR.
- Replies: 14
- Views: 20849
- Tue Jan 23, 2007 1:12 am
- Forum: Phono
- Topic: MC stepups.
- Replies: 86
- Views: 102213
- Sat Dec 23, 2006 6:58 pm
- Forum: Phono
- Topic: MC stepups.
- Replies: 86
- Views: 102213
- Sat Dec 23, 2006 6:34 pm
- Forum: Phono
- Topic: MC stepups.
- Replies: 86
- Views: 102213
It may be worth looking at the LTSpice help for inductors, there seems to be more than just idealised elements avalable. Most of what I read makes little sense to me at the moment, but I suspect it will to you Dave for modeling non-linear behavour. It also does suggest that the parasitic capacitance...
- Sat Dec 23, 2006 11:06 am
- Forum: Phono
- Topic: MC stepups.
- Replies: 86
- Views: 102213
- Sat Dec 23, 2006 1:44 am
- Forum: Phono
- Topic: MC stepups.
- Replies: 86
- Views: 102213
It may be adding too much to the complexity, but it could have bearing as to why its not the clear success Andrew found. I have been thinking about the input of the phono stage, but from the perspective of the first grid. Andrew, you know that when I built the TL LCR stage as T's original design, it...
- Fri Dec 22, 2006 9:03 pm
- Forum: Phono
- Topic: MC stepups.
- Replies: 86
- Views: 102213
Just FYI, I have tried your suggestion, loading the primary (lundahl step ups), it certainly made a difference, but I have gone back for the moment, I will try again later. It seemed to my ears to bring up the lower midrange, also there was a lot more lower bass, and the top end was more detailed as...
- Thu Aug 17, 2006 11:32 am
- Forum: Phono
- Topic: LCR riaa's
- Replies: 96
- Views: 134329
Sorry brain fade, it was and is 300hz. I must get some better better cable and rerun the connection between the listening room and where the computer is to try and get rid of that 50hz. The card I am using is a m-audio 2496. I don't know what the noise floor in 24bit mode will work out, but its good...
- Wed Aug 16, 2006 5:06 pm
- Forum: Phono
- Topic: LCR riaa's
- Replies: 96
- Views: 134329
OK, I don't know if these are any interest , but I wanted to get some idea of the S/N ratio I am getting out of the E810F Pentode front end in my LCR phono. This is a Denon 103 (0.3mv) into lundahl TX's wired for 1:20. The first graph is the background noise, with the phono stage off. It does show I...
- Sat Aug 12, 2006 8:03 am
- Forum: Phono
- Topic: LCR riaa's
- Replies: 96
- Views: 134329
I think Max worked out that the E810F noise was equivalent to a 100R resistor in series with the signal, I assume. Yes, the E810F spec gives its equivilant noise resistance as 110R, however I think that will just be 1/f (it must be, I guess, as its specified by the equiv resistance), I don't think ...
- Thu Aug 10, 2006 7:00 pm
- Forum: Phono
- Topic: LCR riaa's
- Replies: 96
- Views: 134329
I am not at work next week, and was planning to get set up for some loudspeaker measuring. I should be able to do some tests on the pentode driver LCR phono I am using, to try and get an idea what the S/N ratio is. At the moment using a Denon 103 (0.3mv) and 1:20 TX's noise is certainly not an audib...
- Tue Aug 08, 2006 7:05 pm
- Forum: Phono
- Topic: LCR riaa's
- Replies: 96
- Views: 134329
- Sun Feb 12, 2006 2:02 pm
- Forum: Attenuators
- Topic: impedance and frequency response
- Replies: 7
- Views: 6000
- Fri Oct 07, 2005 7:03 am
- Forum: Sim City
- Topic: New Tube Models
- Replies: 7
- Views: 10932
- Sat Oct 01, 2005 1:07 pm
- Forum: Sim City
- Topic: New Tube Models
- Replies: 7
- Views: 10932
Ok, it was only a single line change to get the models working in LTSpice, I have created a new inc file containing them and the original models, and a 6c45pi I found somewhere. I should find the 6n6p model I saw,as I am using one in my phono stage, so I can bring the model up to date. http://www.lu...
- Fri Sep 30, 2005 8:58 pm
- Forum: Sim City
- Topic: New Tube Models
- Replies: 7
- Views: 10932
I have a 6c45 model that does work with LTSpice, Its not mine, so I would have to find where it came from before posting it to,make sure they get the credit. I suspect to get the Koren models to work,I am going to have to sit down and work out how it actually works, instead of mindlessly cutting and...
- Fri Sep 30, 2005 6:58 am
- Forum: Sim City
- Topic: New Tube Models
- Replies: 7
- Views: 10932
I tried adding to dmtriodep as suggested, but spice doesn't seem to like them (the gm70 model anyway),this was lateish last night so I haven't had chance to look further, I will take another look tonight and see why they don't play together. If they do I will create a new .inc with them in if that h...
- Fri Jul 15, 2005 12:57 am
- Forum: Sim City
- Topic: Generic ASC files
- Replies: 11
- Views: 18174
- Mon Apr 18, 2005 8:06 pm
- Forum: Current Cancellation
- Topic: new project, new challenges -> CC IT for 100TH driving GM
- Replies: 17
- Views: 23811