....but why does it ALWAYS seem to be me ?
Why is everyone so frightened of baring their a...
Andrew
Possibly because they are put off by the clever dick know-it-alls, or 'Armchair Experts' as I call them.
There aren't too many on this forum, but all forums have them.
You did prove one thing as well - its not enough to ask dumb questions, you still have to let your ears be the judge and there's no shame in not going for the most complex, 'bees knees' solution thats being pontificated upon by the AEs.
I could not agree more
If there was less knob factor on this forum and more of just helping people and straight out DIY less of proving who has the superior intellect (especially of the more established members of Diyaudio) things would go along so much more smoother and be less of an intimidating place for newcomers to actually find out about the enjoyment of the DIY hobby .
I could not agree more
If there was less knob factor on this forum and more of just helping people and straight out DIY less of proving who has the superior intellect (especially of the more established members of Diyaudio) things would go along so much more smoother and be less of an intimidating place for newcomers to actually find out about the enjoyment of the DIY hobby .
At last.........someone said it !!!
KNOBS.......ask me how much I laughed at that
I could write a list but you'd know who they are.
I do laugh at them now and imagine them with their mundane lives and dominant wives
mmm.. poetry !!
Paul you are a very funny man - that made my day.
Mr Battery in Scotland - you too - my spirits are lifted.
Watch out for more inane and meaningless posts from me in future - just for the hell of it !!
erm ..resistors...what are they for again ?
Andrew
DEM clock frequency may be tuned by varying the value of the capacitor at pins 16 and 17. I have a 400 pF variable capacitor, of the type used in AM radio tuners. I am thinking to connect it to pin 16 and 17 and then adjust the capacitance to obtain a DEM clock frequency of, say, 352.8 KHz.
The question is: How can I reliably measure the (internal) DEM clock frequency without altering it?
I own a frequency meter and a 50 MHz digital oscilloscope with FFT.
Any ideas?
The question is: How can I reliably measure the (internal) DEM clock frequency without altering it?
I own a frequency meter and a 50 MHz digital oscilloscope with FFT.
Any ideas?
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I have wondered for a while if a ceramic resonator could be installed instead of a capacitor.
CERAMIC RESONATOR 350 KHZ - ZTB350D
CERAMIC RESONATOR 350 KHZ - ZTB350D
I think I read somewhere that you have to measure off one of the decoupling pins with the 100nf capacitors.
Did you apply the DEM modding to an oversampled DAC or to a non-oversampling one?
Which frequency was used to feed DEM pins?
Did you inject BCK without dividing it? Or WS, as in the Grundig circuit?
Hi Erin, I've been wondering about that very thing. I'm thinking of trying the Grundig mod on my Analogmetric Dac. It really sounds better? My DAC is a little different. I'm running a NPC digital filter with glue logic instead of the 7220. OPA603 I/V 7th order GIC Bessel filter and OPA627 output buffer. For whatever reason I've never heard any glitches or misbehavior using the Analogmetric reclocking (Hagclock at 11.2896 MHZ). My second build is another story however. Wasn't so lucky on that one. Dave
. Wasn't so lucky on that one. DaveGood question. It is NOS
I used WS. I built the Grundig circuit exactly as in the schematic. Though I do realise the DEM frequency is technically too low. I probably should try it using BCK.
Ahh, another good question. I initially tried the inverter method(ec designs), (again on non oversampling) and convinced myself that it sounded better, it certainly was a "tighter" sound across the frequency range. However, upon comparing to my friends dac which is exactly the same, but just had a 560pf cap across p16/17. I was quite shocked to find that my dac just did not sound as good his. My dac sounded sterile, and un-dynamic. Basically on his dac, with the cap (regular TDA datasheet DEM circuit) the music flowed really nicely, was dynamic and vibrant, you know, the way a TDA should sound, that sort of sound that people like about the TDA1541. So I ended up putting a cap back in on mine.
Later my friend wanted to try the Grundig method of reclocking so I installed the Grundig method on his dac, when we listened, at the time, we both agreed that the Grundig method allowed the same dynamic, flowing, musical sound as a cap across 16/17, but did give more detail and cleanliness to the sound.
I have since applied the Grundig method to my DAC.
Actually I am not really convinced that DEM re-clocking is the be-all and end-all. Its more of a change of sound, than a 100% improvement. It is a cleaner sound. But, some of that vibrant bold TDA sound can be lost.
Some may appreciate the cleaner top end and tighter cleaner bass that DEM re-clocking provides, but some may miss the pleasant "je ne sais quoi" that comes with the original cap across pins 16/17. I think it's up to the individual to decide.
For anyone else wondering if they should try Dem re-clocking, I'd advise not to loose any sleep over it.
Please allow me to finish with one more comment, if you want a cleaner sound, there is only so far you can go with a TDA1541.
If you want to get the same analog sort of sound with nice midrange, such as with a TDA1541, just cleaner, try one of the many mono Burr brown R2R Dacs, you may just find that they provide the sound that you are after.
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Hi Erin and Mayday, Thanks for the comments. I am using 470pF polystyrene cap at 16/17. I think I'll just give a smaller value silver mica a shot. Yes, I do like the 1541A sound. Image depth may not be as deep sounding as some it's just one of the most musical sounding parts around. I'll try something in the 100 to 250 pF range. Thanks again, Dave
These are the values that result in a lock(taken from UV101's PDF)
EDIT: the cap really should be 1% tolerance.
Here's one if you have trouble finding them.
EDIT: the cap really should be 1% tolerance.
Here's one if you have trouble finding them.
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Hi Mayday, Happy New Year. Wow those are sure big caps. I found some SMT PPS caps at Mouser. I'd probably have to buy a few and measure them. I do have access to a measuring device. I downloaded UV101's paper on reclocking. A wealth of knowledge there. Like you I'm on a budget and buy parts over time. Nothing wrong with that. The schematic you posted is a good place to start on your tube output stage. If you use a resistor for I/V make sure to pick the absolute best you can find. That is the most critical one. Low inductance is key. Save up if you have to! This week after I do a few chores for my aged Father I will dig into that Magnavox player. The smell is something "Hot". So not to hard to find I hope. If I get the bug I may look at clock buffers and figure out if I want to try slaving the CDB650 (as a transport) to clock on the outboard Analogmetric DAC. If nothing else an interesting experiment. Dave
This week after I do a few chores for my aged Father I will dig into that Magnavox player. The smell is something "Hot". So not to hard to find I hope. If I get the bug I may look at clock buffers and figure out if I want to try slaving the CDB650 (as a transport) to clock on the outboard Analogmetric DAC. If nothing else an interesting experiment. Dave
Ferite bead and op amp power supply
two mods that I have made.
one replace r17 and c34 with a ferrite bead (muRata)
two install 10uf/50v Panasonic FC from opamp power pins to analog earth to improved power supply decoupling.
Both mods improved sound a bit in my opinion.
Has anyone else tryed these?
two mods that I have made.
one replace r17 and c34 with a ferrite bead (muRata)
two install 10uf/50v Panasonic FC from opamp power pins to analog earth to improved power supply decoupling.
Both mods improved sound a bit in my opinion.
Has anyone else tryed these?
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