[Jon L]

Quote:

Originally Posted by bizkid /img/forum/go_quote.gif compared to the Jan philips which was alot worse at 0,17x something vs 0,0xx for the sovtek, also the philips arent matched and so they show a L/R difference of 0,3dB, the sovteks dont show it. That were the only big differences between them. Still the Philips sound MUCH better than the sovteks, funny.. Ill get my amperex back in a few days, really looking forward to measure them. .

I'll bet the Amperexes measure even worse than JAN Philips.

Sovtek 6922 is perhaps one of THE worst sounding tubes I've ever heard of any tube type/brand out of hundreds I own/tried. It just was no good. It's strange b/c I kind of like Sovtek 12AX7, EL84, etc.

 

[Capo]

Steve,

It sounds like you bypass the DF1704 digital filter on your dac60 mods?

Thanks. Bill

 

[Ruach]

Hi guys, especially to those who own the the tubed-Lite DACs,

There are a number of modifications that you can do to your sets, be it the Lite DAC50, 60 or 72.

The improvements that I have heard in these mods are pretty significant - and these include tightening of the bass, increasing the staging as well as the extensions in the highs.

A very quick and simple mod is to add in a cathode bypass cap as seen in Monarchy's M24 dac (which is a modded version of the Lite DAC50).

This mod improves significantly on the mids and highs. Even the Sovteks sound good with this mod.

A Christmas modding tip for Christmas

 

[Ruach]

For the more adventurous owners, the Lite DACs can be modded to accept the Russian supertube 6H30P, which is used in nice components made by Conrad Johnson, BAT, Cary Audio, ARC...

You will need to up the filament current and rebiased by changing some resistors.

You will have to cut a hole on top of the chassis as the 6H30P tube is a bit too tall for the chassis.

The 6H30P, IMHO, sounds better than any 6922 tubes that I have came across.

 

[Capo]

Gee, Thanks Ruach, very nice of you to mention those mods.

Regarding the cathode bypass cap. What is the size of the cap on the Monarchy and where is it located on the circuit board. Is it a bypass on the 6dj8 cathode to ground resistor?

You wouldn't have a schematic of the Dac50/60/M24 you could shoot me, would you?

 

[Ruach]

Check out the two caps on the left side of the picture. The cathode bypass caps are right next to the tubes.

 

[Capo]

Ok, I think I see them, not sure, there are two groups of caps there. In any case I'll need more info to make the mod. Any idea on what parts on the board (with part number that shows up on board) I am bypassing.

Also, do you know the values of the cathode bypass caps I'll need?

 

[bizkid]

The DAC60 has 2 small wima caps next to the tubes. Do you actually mean to replace them with the electrolytics as in the monarchy? What value is used in the monarchy?

 

[Ruach]

When you guys get home tonight or if you are at home right now, open up the casing of your Lite DAC and you will notice that two caps are missing from your DAC when compared to the picture of the M24 that I have attached.

Bizkid - I am not referring to the red Wima caps though it is a good idea to replace them with something nicer like Auricaps.

I can start a new thread on modding the Lite DAC if there is sufficient interest. It's almost Christmas time and it's a good time to spread the joy by sharing some modding tips

The Lite DAC is a well-built DAC at a great price. Stock versions of the Lite don't sound nice though - poor definations in the bass and highs and the mids are rather recessive. Tube rolling to better tubes helps a bit but not much.

IMHO, the caps mods that I have mentioned just now will set you back by less than $20 (a nice pair of 220uF 16V Blackgate or 180uF 20V Oscon will do the trick) but you will get $200 worth of improvements in return.

 

[bizkid]

Thats how my DAC60 looks. If its not the 2 wima caps, then what is that cap connected to? The resistors? There is only 1 free place on the PCB above the wima, where would the other end of the cap go?

A dedicated thread about modding the DAC60 would definately be interesting

 

[Ruach]

The cathode bypass caps are soldered over the resistors in the case of the M24.

This is a undesirable way to install in the caps as they will be next to the hot tubes. Heat and electrolytic capacitors don't make good bed fellows

I will take a look at the drawings and get back to you on the actual positioning of the parts on the board.

 

[bizkid]

Ah i see. it would not only get hot in there from the tubes, but i would need a seriously quiet hand while soldering

I can already see some burned parts on the PCB from accidentally touching with the soldering iron

Thanks alot for your help.

 

[Ruach]

The soldering should be an easy job.

Solder the caps to the solder pads of R10 and R12. Use a pair of twisted wire to locate the caps away from the tubes.

I would recommend to the owners of the M24 DAC to do the same. Most electrolytic are rated at 85C and prolonged exposure to the hot tubes will shorten the life of the capacitors.

Try it and report back to us how your Lite DAC sound with this new mod.

Have fun!!!

 

[Capo]

Thanks, I'll try it.

I am not too crazy about using electrolytics, particularly in that location, but it is an easy thing to play around with in any case.

Do you know what the other differences are between the Monarchy M24 and the Dac50/60?

 

[003]

Quote:

Originally Posted by Ruach /img/forum/go_quote.gif A very quick and simple mod is to add in a cathode bypass cap as seen in Monarchy's M24 dac (which is a modded version of the Lite DAC50).

Does anybody know if this is done in the sonicraft mods?