Preamp
Hello!
What are your recomendations on preamp to the trend amp.
I'm gonna use 2 mardis modded amps and want a good preamp for this project.
I am thinking of some kind of tube preamp.
Hello!
What are your recomendations on preamp to the trend amp.
I'm gonna use 2 mardis modded amps and want a good preamp for this project.
I am thinking of some kind of tube preamp.
For a change I might have something to add! I have a Mardis fully kitted T-10. I only had one IC on hand, a DH Labs Sonic silver. I had a very similar experience with the sweet spot being in a narrow range. By chance I got to loan an old (veryold!) cable that I sold years ago; A Straight Wire Maestro. I think it dates from the early 90's.
Totally opened up the sweet spot and really locks in nicely. If anyone can find a pair (e-bay?) I highly recommend. Should be cheap by now (and well run in!)
Totally opened up the sweet spot and really locks in nicely. If anyone can find a pair (e-bay?) I highly recommend. Should be cheap by now (and well run in!)
t. said:
Hi t,
If you're using stranded auto cable, try Maplins 16G enamelled copper wire (single core). It is surprisingly good and cheap - though not so easy to lay. Some of the Mapleshade hifi cables seem to be simply woven enamelled wire. The problem with cables is they are expensive and need burnt in and long listening to appreciate. I came close to buying 9999 silver wire and teflon sleeving, but found secondhand Ultraconductors after reading the TNT review and they turned out to be very good. I tried one cat-5 recipe and didn't like it - consistently a sort of thickness to the sound (though I didn't do the full unravel-every-strand and re-weaving thing).
Because of the rubbishy connectors on the SI t-amp I used the enameled wire with them and it was a stunningly good combination - the SI t-amp did not sound so good (in my system) with the expensive Ultraconductors.
Good luck, Alan
Shiznit said:
The Dared SL2000a seems highly recommended. Another, Prometheus Audio TVC, is a popular non-tube variety. I've read positive comments on both from Trends users, but I haven't used either on the amp before. I personally plug straight into my source.
Preamp?
If you want a budget solution that sings, try a shunt modded ALPS Blue. My 50K pot is shunted with Dale RN55s and then parallelled with a (same make) resistor network to get 25K (for more volume). It's cheaper than most solutions and sounds great!
http://www.pinkfishmedia.net/forum/showthread.php?t=13921&highlight=shunt
http://www.pinkfishmedia.net/forum/showthread.php?t=25486&highlight=shunt
Thanks to the guys on PFM for the pic - it's not mine. Also, a word of warning; I wired mine up back to front when I first built it. Volume change in a very small range (of pot turn). A quick "pointer-out" from t. and a 2 minute resolder and I was in business again!
Have fun!
Jon
If you want a budget solution that sings, try a shunt modded ALPS Blue. My 50K pot is shunted with Dale RN55s and then parallelled with a (same make) resistor network to get 25K (for more volume). It's cheaper than most solutions and sounds great!
http://www.pinkfishmedia.net/forum/showthread.php?t=13921&highlight=shunt
http://www.pinkfishmedia.net/forum/showthread.php?t=25486&highlight=shunt
Thanks to the guys on PFM for the pic - it's not mine. Also, a word of warning; I wired mine up back to front when I first built it. Volume change in a very small range (of pot turn). A quick "pointer-out" from t. and a 2 minute resolder and I was in business again!
Have fun!
Jon
Attachments
I'm using a Transcendent Sound GG (tubed) pre in front of my TA 10.1 It makes very sweet music. I tried the Trends with a SS pre, and just using its own volume pot. It's not the same amp w/o the tubed pre, IMHO.
Don
Don
After listening to the amp after removing the 100pf caps, I really think the high frequency sounds better. There is less distortion in drum cymbols that has been bothering me before. Also, I removed the casing and have it laying flat on a bamboo cutting board right now. The casing seems to have an effect on the sound, although a subtle one that I feel more than I hear. I feel like I need to build a wooden case for this amp, as the sheilding from the casing is affecting the sound. I need to do it anyway since the Obbligato PIO's have nowhere to go. I should have the Caddock resistors at the end of the week.
I will also build a new wooden case for my two amps.
I'm gonna use one amp do drive the woofer elements and the other to drive the midrange and high freq.
Which Power cap if you don't think about the size and price is the best one for the trend amp to use it for the woofers in my speakers.
Should i try Obligatos instead of the cap mardis uses in his modification?
or what do you think?
I'm gonna use one amp do drive the woofer elements and the other to drive the midrange and high freq.
Which Power cap if you don't think about the size and price is the best one for the trend amp to use it for the woofers in my speakers.
Should i try Obligatos instead of the cap mardis uses in his modification?
or what do you think?
Depends on what flavor of sound you want... The Auricaps will probably be more neutral. The obbligatoos sound fullbodied/ warm.
I think they will make a bigger difference.
I think they will make a bigger difference.
Alan Hope said:
Thanks Alan, I'll check it out🙂
Sounds like you had similar results as me regarding the Cat5, I tried both the standard and twisted twins recipe, didn't like either tbh.
Funny thing is out of all the cable I've tried the cheapo auto cable gave me the best balance.
You try something like the UCD mono's and these speakers really do sing, the little Trends is ok for late night listening and has the advantage of being portable
Please remember that the RFI caps not only keep RF out, they keep in IN! That;s why some T-Amps also use ferrite beads on the inputs.
Believe me, a lot of noise gets sent down the input lines. With the right equipment you will easily find it in your preamp and/or your sources.
How your preamp and source handle it is another question, but it's probably not good to flood them with RF.
Believe me, a lot of noise gets sent down the input lines. With the right equipment you will easily find it in your preamp and/or your sources.
How your preamp and source handle it is another question, but it's probably not good to flood them with RF.
Thanks pano, as usual. Everything just sounds better for now witout the caps. Once I get some better caps, I'll put them in and hope that the sound quality doesn't diminish.
By the way, is there ever going to be a complete Mardis T-amp? Not just a modified one, but one designed by you from the ground up. It would be nice to see....
By the way, is there ever going to be a complete Mardis T-amp? Not just a modified one, but one designed by you from the ground up. It would be nice to see....
Hi,
in the modification on your site, does the input path mod keep RF caps or not ?
All the best
Thanks
Alessandro Fogar
in the modification on your site, does the input path mod keep RF caps or not ?
All the best
Thanks
Alessandro Fogar
panomaniac said:
What is the material of the yellow caps throughout the board? Has anyone thought to change them out?
Most probably MKS or MKT because of the small size and the low voltage ratings (63V), Both types are not known for their good sound quality but in this application it would be hard to find any good replacement caps because size is a major issue here. Not only the limited space on the circuit board but the size of the capacitors themselfs aswell. Bigger caps have more self inductance and are more "antenna" area to pick up and send out high frequency components. Even the leads of the bigger caps could have too much self inductance.
Other than that replacing these caps can certainly be a big improvement I think, but choice is very limited
Other than that replacing these caps can certainly be a big improvement I think, but choice is very limited
I've waited before posting this, because I have very mixed emotions ... elation and slight embarrassment, and I wanted a long listen to confirm my findings
Persistently unhappy with my system sound, despite the improvements changing the TA-10.1 RFI caps, I tried a number of tweaks.
1. Swapped my JPS Ultraconductor speaker cables for some Nordost. Three CDs later the JPS were back. They walk the Nordost in all aspects.
2. Suddenly remembered I had a pair of Rothwell Attenuators lying around. Given that my sweet-spot Vol pot range was 8pm to 10pm I inserted these at the inputs. This gave me use of the full 360° turn of the Vol pot. I was hoping simply to improve the low-volume 'closing-in' that irritated me. Ran 4 or five CDs at near full volume which was lound/comfortable listening. There was no major distortion - but a slightly shouty dynamic, a hint of grain, and a definite loss of low level detail. Low volumes were perhaps slightly improved, but not dramatically. Took out the Attenuators, dropped down to equivalent volumes, ran the same CDs and everything was better ...
And here was my big surprise. Everything was MUCH better. Unbelievable MUCH better!!! High frequencies had opened out and sweetened dramatically, the soundstage was deeper and wider, low volumes were fine. I was hearing the best amp I had ever heard.
I have now listened for many hours - critically - to a set of CDs which I know inside out: with a wide variety of sonic challenges. Including Massive Attack, Bach "German Requiem", Garbage, Gershwin, Joni Mitchell, King Crimson, Television, Martin Stevenson, Paul Simon, Norma Waterson, Queen, Oscar Peterson etc etc
Improvement confirmed, and no sign of sound quality varying in any way. What the heck has happened? Did the fully open playing with the Attenuators in somehow complete the burn-in process? Did some component pop into it's correct spec?
Worse - were my moans to Trends premature? Was my burn-in - which was necessarily low volume during the night - too low volume to work properly, so was I girning about a not fully burned in amp? Perhaps the RFI ceramic caps would not have mattered after all.
I owe David Ho an apology, I think. Though the concept of an amp that needs such an extended burn-in is strange - particularly when some folk were saying, "it sounds great right out of the box." And unlike cables, for me - the final improvement was like a swwitch being turned on.
I am so so so happy with the sound. I was starting to look at new speakers (Klipsch?) ... not any more. The IPLs sound fantastic!
t. - try and get some JPS Ultraconductor speaker cables to try. Mine were 2nd hand, so already burnt in, and I can't fault them. They have a good reputation for longevity too. (See the TNT review for a second opinion).
No more mods for me, I'm going to get some CDs! 🙂 🙂 🙂
Persistently unhappy with my system sound, despite the improvements changing the TA-10.1 RFI caps, I tried a number of tweaks.
1. Swapped my JPS Ultraconductor speaker cables for some Nordost. Three CDs later the JPS were back. They walk the Nordost in all aspects.
2. Suddenly remembered I had a pair of Rothwell Attenuators lying around. Given that my sweet-spot Vol pot range was 8pm to 10pm I inserted these at the inputs. This gave me use of the full 360° turn of the Vol pot. I was hoping simply to improve the low-volume 'closing-in' that irritated me. Ran 4 or five CDs at near full volume which was lound/comfortable listening. There was no major distortion - but a slightly shouty dynamic, a hint of grain, and a definite loss of low level detail. Low volumes were perhaps slightly improved, but not dramatically. Took out the Attenuators, dropped down to equivalent volumes, ran the same CDs and everything was better ...
And here was my big surprise. Everything was MUCH better. Unbelievable MUCH better!!! High frequencies had opened out and sweetened dramatically, the soundstage was deeper and wider, low volumes were fine. I was hearing the best amp I had ever heard.
I have now listened for many hours - critically - to a set of CDs which I know inside out: with a wide variety of sonic challenges. Including Massive Attack, Bach "German Requiem", Garbage, Gershwin, Joni Mitchell, King Crimson, Television, Martin Stevenson, Paul Simon, Norma Waterson, Queen, Oscar Peterson etc etc
Improvement confirmed, and no sign of sound quality varying in any way. What the heck has happened? Did the fully open playing with the Attenuators in somehow complete the burn-in process? Did some component pop into it's correct spec?
Worse - were my moans to Trends premature? Was my burn-in - which was necessarily low volume during the night - too low volume to work properly, so was I girning about a not fully burned in amp? Perhaps the RFI ceramic caps would not have mattered after all.
I owe David Ho an apology, I think. Though the concept of an amp that needs such an extended burn-in is strange - particularly when some folk were saying, "it sounds great right out of the box." And unlike cables, for me - the final improvement was like a swwitch being turned on.
I am so so so happy with the sound. I was starting to look at new speakers (Klipsch?) ... not any more. The IPLs sound fantastic!
t. - try and get some JPS Ultraconductor speaker cables to try. Mine were 2nd hand, so already burnt in, and I can't fault them. They have a good reputation for longevity too. (See the TNT review for a second opinion).
No more mods for me, I'm going to get some CDs! 🙂 🙂 🙂
Sjef said:
I've been contemplating swapping them out. The closest readily available replacement I could find were Wima MKP2 polypropylene; however, I was thinking maybe I should recase and try bigger alternatives on top and bottom to fit into the space. Are there any other cap suggestions that might work? If space were not a major concern, I wonder how good these amps could really get.
One interesting thing I noticed recently was the breaking in process. With the new input caps and power tank caps, I noticed a sudden dramatic improvement in what seemed like a span of 2 hours after a couple days of playing. I thought I was imagining it, but the next day, the sound improvement stayed and hasn't disapeared yet. Very interesting. Sometimes I wonder if people really ever give mods a chance to settle before changing things some more. Or maybe I'm the one that's changing......
Alan. I have found that there is no substitute for "not sparing the horses" !. Give it lots of welly. Bit like in the olden days you used to have to run new engines in and change the oil after 500 miles. First oil change is now usually 18,000 ! and they actually benefit from being abused. Until recently I had a Clio sport Cup. Great car, but roads too busy to really use it. Now I am growing old gracefully with a 1.4 16v Megane. It can do 99% of the things I could do with the Clio, including going round bends very quickly !
dweekie said:
It's going to depend on which ones you change. They do different things in the circuit.
The 2 yellow caps nearset the chip are on the swtiching power rail. These really should be SMD caps right at the chip pins. I have a design in the works that uses 2x 0.1uF in this postion.
The others you see near the coils are the filter caps and the Zobel caps. They form the 2nd order low pass filter to remove the RF from the output. Play around with those to your heart's content. Try to keep the leads short though.
One of the trouble areas in a class-d amp is the voltage bounce when the power transistors turn on and off. There can be a lot of enegry in the coils that bounces back - very much like an ignition coil in a car. The diodes are there to help tame this bounce or overshoot.
So you have to be a little careful with the outputs, are you risk killing your output transistors. But it sholdn't be a big problem. Changing the values in the output filter can change the frequency responce in the top end.
As for the little RFI caps at the inputs, I really don''t know. They are of such a small value that they can't be doing much to the audio band. At least that's the idea.
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