The Dared SL 2000 modification thread

george daniel

First of all,,a little entertainment--I was fortunate and got to see him and this band just recently,,here's a ten and a half minute taste.

http://www.youtube.com/watch?v=yowJiQZBXrA


Lets start with tubes. Currently running a Bendix 6106 rectifier and a pair of Sylvania 5965's I'm hoping that Brock,KiekoFGTV and others will chime in,as they have far more experience with tube rolling/schematics in this unit.I have the schematic's and can e-mail them to anyone who needs a set.First and foremost,this thread should be fun,and tube rolling is the easiest,but can get expensive.In the pic's you'll see where I remover the input caps,and replaced them with .22 400 volt Russian PIO(wrapped in black tape-IIRC the case is conductive)They are too big for the board,so I mounted them on the inside chassis,and ran wire from the board to the caps.I think a good cap in this position would be an Auricap and/or Sonicap and a good vintage PIO.

One thing that I noticed,,the Sylvania plates are offset.

george daniel

The green wires attach the cap(black) to the board.If you decide to perform this stage,,take your time as there is not too much room to work,,simply de-solder the on board caps(1 for each tube) and resolder you caps or wire leads,whichever you choose.This part is pretty straighforward.Next up will be the Obligatto caps to replace the stock coupling caps.And,,as soon as they arrive,I'll post a step by step photo pictorial,hopefully.

fishbones

Glad to see my unit getting so much love and attention (hey, that sounded kinda weird). Enjoy George!

george daniel

Thank you sir-- here are some helpful links guys

http://www.polkaudio.com/forums/showthread.php?t=120448&highlight=dared

and here,,Brock has the best pic's,,mine suck

http://www.polkaudio.com/forums/showthread.php?t=117770&highlight=holy+grail

heiney9

To chime in about the tube rolling, one of the things about the Dared Sl2000A is it uses 12AT7's and equivalents instead of the ultra popular 12AX7's. This means tube rolling won't put as big a dent in your pocket as with some other tube pre-amps.

There are some superb 12AT7/ECC81's out there and they won't break the bank. I also own a tube integrated that uses 12AX7/ECC83's and it can get expensive quickly with 12AX7's because of the whole demand/supply issue.

Also this is a tube rectified pre-amp and I think that's what gives it such great tone and soundstage. The Brimar and Bendix have been simply superb sounding rectifiers and again not a lot of money. My other tube integrated uses a 5AR4 rectifier (probably the most popular) and the only one worth a damn is the Mullard and they are very expensive.

I look forward to more photo's and step-by-step from George. I have the Auricaps already and would love to change the yellow Carli coupling caps to something a little more musical.

H9

FTGV

George ,space looks a little tight is the PC board easily removed to get access to the solder pads of the output coupling caps?

george daniel

FTGV wrote: »

George ,space looks a little tight is the PC board easily removed to get access to the solder pads of the output coupling caps?

Great point Fred-- I was able to partially remove the board enough to expose the solder points.I am gonna' have to "think thru" the output cap installation as I'm running out of real estate quickly.Thoughts?

While we are on the subject of boards,,I did noticw some brown "goo" on the board when I removed the Bendix,,nothing burned,,goo was on the tube too,,and not there to begin with.Any thoughts?

FTGV

george daniel wrote: »

Thoughts?

If you can atleast get access enough to cut the leads of those film caps.Then you should be able to desolder them to add flying leads as you did with the other pair.

While we are on the subject of boards,,I did noticw some brown "goo" on the board when I removed the Bendix,,nothing burned,,goo was on the tube too,,and not there to begin with.Any thoughts?

Excess solder flux maybe?

george daniel

flux,, hmmm thanks--and yep on clipping the old caps ,,that's my plan for now--now if the folks from Partsconnexion will get the caps out,we'll pop these puppies in soon,,and I'll be done,,hopefully.

heiney9

Can you take a photo G? Which Obligatto's did you get?

FTGV

george daniel wrote: »

now if the folks from Partsconnexion will get the caps out,we'll pop these puppies in soon,,and I'll be done,,hopefully.

We had a mail strike but the posties have been forced back to work so there may be a short delay.:frown:

george daniel

heiney9 wrote: »

Can you take a photo G? Which Obligatto's did you get?

these

http://www.diyhifisupply.com/catalog/23

heiney9

george daniel wrote: »

these

http://www.diyhifisupply.com/catalog/23

Did you get them from Partsconnexion or from diyhifi (Hong Kong)? PC has them $2 cheaper plus another 20% off. It will be interesting to see how they fit. I am heavily leaning toward the REL Multi Cap PPMFX because they are physically smaller since they are 400v. They are same caps I used on the Adcom around the Op-amp section and they sound fantastic.

I await your findings on the Obligatto's

george daniel

heiney9 wrote: »

Did you get them from Partsconnexion or from diyhifi (Hong Kong)? PC has them $2 cheaper plus another 20% off. It will be interesting to see how they fit. I am heavily leaning toward the REL Multi Cap PPMFX because they are physically smaller since they are 400v. They are same caps I used on the Adcom around the Op-amp section and they sound fantastic.

I await your findings on the Obligatto's

Partsconnexion,, I like the pic better from DIY HiFi--they get good review's,,German made IIRC--the multicaps are very size conscious/oriented--thats whats in my Jolida, and I think the cost to "better" them is prohibitive--good choice sir,,my main issue is gonna be removal of the current caps-but I'll get it figured out.

heiney9

I'll wait until you have completed yours and worked out the kinks . I've been wanting the try the Obligatto's in something, but I'm NOT an electronics wizard so if it's pretty much not "plug-n-play" I'm a little gun shy. The REL Multicap seems to be more plug-n-play, but we'll see how you do so I can gauge if I can do.

Just so I'm reading the schematic right (4) 1uF 400v in that position?

Now I really wish I would have bought those pair of new boards listed on e-bay. They went for about $60.00 shipped. You could have had one and we both could have repopulated those and just swapped the boards out.

H9

george daniel

Brock-- I am far from an electronic's wizzard--I'm a "paint by the numbers" guy,,FGTV get's the credit for the "wizzardry"

heiney9

george daniel wrote: »

Brock-- I am far from an electronic's wizzard--I'm a "paint by the numbers" guy,,FGTV get's the credit for the "wizzardry"

Did I get the values right (4) 1uF 400v?

Yes, Fred is great and very helpful. We don't always see eye to eye and I seem to come off gruff at times (according to him), but I consider him one of the most knowledgeable people here and follow his advice w/o question when it comes to undertaking mods like this.

H9

george daniel

Yep-- 1uF/400 volt 2 each per channel.

george daniel

next up

FTGV

Dem's purdy.

george daniel

Okay-- as I move along,I have decided at least at this point to "mount" the caps externally to the chassis,,I had to remove the faceplate/voulime control and then was able to get the right exposure to the board for de-soldering.soldering wires for the caps--they are just too large for my skill level to attach inside the chassis,so I'm taking the easy way out.For anyone wanting to perform this mod,,I would suggest a much smaller cap,,MIT,etc,as they should squeeze on to the board.The red wires that you see in the pics(8 total) will be the Obligatto 1Uf (coupling) caps. The wires towards the front of the unit are the input caps(green and black ones) to which I have the Russian PIO's.I'll post some pics of the external box.Hope this helps.

Outfitter03

George is it the length or the diameter or both that make these hard to fit? Were you able to remove the PCB board or did you have to reach back in that distance with your soldering iron to get the 1uf capacitors out?

Thanks for the updates!

george daniel

Outfitter03 wrote: »

George is it the length or the diameter or both that make these hard to fit? Were you able to remove the PCB board or did you have to reach back in that distance with your soldering iron to get the 1uf capacitors out?

Thanks for the updates!

Actually both,, I was able to get the board out and desolder without any issue,,it requires removing the smaller board in the rear--2 screws--easy enough,,then remove the faceplate(two internal/chassis screws(wood) from the inside,,wood faceplate comes off-- then the sheet metal on the front has one screw--one off--the board slides forward and up/out.I could have mounted the caps in/on the chassis,,but if I ever need to go back in,I would have to remove them first,, so either smaller caps which can be mounted to the board,,or my "external" box,,which I can live with(personally)--.

george daniel

Well,, it works just fine so far,, now for the caps to burn in and for me to get familar with them,,,first impression,,I would say,,a bit better midrange with a very smooth sound to it,very pleasant and no "edginess" to the ears,,not too unlike and oil cap.

george daniel

Well,, it ain't the prettiest,,but I was able to get em' mounted inside,, I'm gonna clean it up,wire it,,and I'll post more,,if they are prettier.My 'paint" skills suck too--but I wanted to get them labeled,so please excuse,,,and no smart a$$ remarks.:rolleyes:

george daniel

Hopefully this is better/makes sense--the input caps are re-located to the inside of the chassis and hot glued,,you can see three of the Obligatto's,,there is one not pictured because it is attached to the inside chassis in the lower right of the pic,,the cap that you can see(lower right) is stacked on it--after determining that I could not get these mounted on the pcb,,I soldered wires in place of the original caps,,placed the board back,,hot glued the caps,,soldered the corresponding wires to the caps,and done.Hopefully this pic helps somewhat.Thanks for looking.BTW--if anyone is looking at performing this mod,and you want to use the Obligatto's,,shoot me a pm--I have four extra 1uF/400 volt cpas,new,in bag/box.

heiney9

Looking good George! How does that Brimar rectifier sound?

george daniel

Brimar is great-- the syngery between it and the Sylvania's is sublime--add the caps--more sublime-- I'll keep ya'll posted--so far,so good.

heiney9

Mike, I let one of my 1940's Brimar from my stash go.

Gald you are enjoying it George......the Brimar still has the best overall tone. The Bendix 6106 does have slightly tighter bass response.

H9

heiney9

I still have a Bendix 6106 here w/ your name on it.

I also am probably putting a pair of 1957 RCA 5965 3-mic black plate, square getter up for someone. I bought a quad and only need a pair. Nice, warm tubes.

H9

george daniel

Just a quick update-- the Dared is sounding very musical and fast--I am however gonna play around with the Obligatto's placement,,as in outboard.The problem is that I can tap on the pre and hear it thru the speakers.I'll re-locate them and update tonight.