[kingnubian]

Nubian, if you have specific questions about the B1, you should probably ask them in the B1 thread. And reading the whole thread is a good idea if you get the chance. It may be 26 pages, but the two original diyaudio.com threads come to about, oh, 400+?...

Just spent part of this evening reading over the thread again. Got all the info I was asking for with respect to parts substitutions even if the boss wasn't too happy at all about the computer time.

[rwolters]

Hi Kingnubian,

Since you've taken the time to review the B1 thread looking for component parts upgrades, can you share what you've found?

Based on your review, do you still have interest in the "Jim's Audio" B1 kit? One stop shopping would be nice, but not if you need to upgrade all the parts to get top performance.

Thanks for your help.

Bob

[kingnubian]

Hi Kingnubian,

Since you've taken the time to review the B1 thread looking for component parts upgrades, can you share what you've found?

Based on your review, do you still have interest in the "Jim's Audio" B1 kit? One stop shopping would be nice, but not if you need to upgrade all the parts to get top performance.

Thanks for your help.

Bob

I will probably go with the PCB with matched JFETS directly from Pass Diy. I want total control over the build and will choose the components based on the recommendations & observations in the B1 thread. While the one stop shopping would be great, and I'll probably go that route with my next build, being that I'm new to DIY I want to really jump in & get both feet wet.

I've looked at what's been posted about the increase in sonics when using higher quality resistors such as the Naked Vishay TX2575 (330R I believe, can someone confirm??) in the input position R102 & R202 while Rikens were used in R104 & R204. I wonder why Naked Vishay's can't be used for all 4?

I'm also continuing to read the B1 thread to get some insight on swapping out the caps to something "better" although so far it seems that the resistor swap leads to the greatest performance increase.

The price will definitely go up, The Naked Vishay resistor mentioned above goes for $15.95 CAD a pop at Parts Connexion here in Canada. IMHO it is still wroth it as this build, at least in my situation, will be put into the system I listen to most often.

Here is a link to the Cap thread right here on Audiocircle.
http://www.audiocircle.com/index.php?topic=54218.0

I will start ordering parts on Monday so I still have some reading to do.

[dvenardos]

I don't have experience with the Pass B1, but sonicaps are very clean and neutral sounding caps.

[kingnubian]

I don't have experience with the Pass B1, but sonicaps are very clean and neutral sounding caps.

Thanks for the heads up. I'm looking into them as I write this.

[walkern]

I bypassed the stock BOM recommended Janzen input and output caps with Sonicap IIs and although they took a while to settle in, I've very happy with the net improvement (a little more 3D in the soundstage, and a little less forward sound, without sacrificing detail).  They are dirt cheap, and I've read that some folks even bypass the Sonicap type 1s with small value IIs.

N

[kingnubian]

Ok parts have started being ordered.

So far I have ordered the essentials.

Solder: http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=200512814272&ssPageName=STRK:MEWNX:IT#ht_500wt_1154
Wire: http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=380260258379&ssPageName=STRK:MEWNX:IT#ht_500wt_1154
Attenuator: http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=120502791204&ssPageName=STRK:MEWAX:IT#ht_4201wt_911


To be ordered Later this week:

Caps (1uf & 10uf Sonicap Gen1)
PCB ( Pass Labs with matching JFETS)
4x Naked Vishay TX2575 330r Resistors
Rest of Electrical components


Can someone tell me the exact dimensions of the PCB (WxLxH with caps installed) so I can choose an appropriate chassis?
I'm looking at these so far for the final "In my component rack" build.

http://www.diyhifisupply.com/node/454
http://www.modu.it/galaxy.html

[walkern]

According to the Gerber files at Pass DIY the board is 7.5 inches by 3.25 inches.  I don't think they specify the thickness of the board, but it can't be much over 1/8".  Keep in mind that the height you'll need to accommodate with your chassis will be determined by the height of your power supply caps more than anything else... so you may want to wait until you have everything before deciding what chassis to use (since the power supply caps are one of the options for things to upgrade).  Just a thought.  I decided on a chassis before I populated my board, and it turned out to be just barely tall enough, and generally a real pain in the keester to work with because it was SO compact.  Oops.

Neil

[jw87c]

Kingnubian, other than the Sonicap Cap and Naked Vishay Resistors, are there any other parts you plan to upgrade? I'm also thinking of building a Pass B1, but I'm too lazy to read the original building thread. Maybe I'll just follow whatever you use in your build  . Please keep us posted on your progress 

[kingnubian]

According to the Gerber files at Pass DIY the board is 7.5 inches by 3.25 inches.  I don't think they specify the thickness of the board, but it can't be much over 1/8".  Keep in mind that the height you'll need to accommodate with your chassis will be determined by the height of your power supply caps more than anything else... so you may want to wait until you have everything before deciding what chassis to use (since the power supply caps are one of the options for things to upgrade).  Just a thought.  I decided on a chassis before I populated my board, and it turned out to be just barely tall enough, and generally a real pain in the keester to work with because it was SO compact.  Oops.

Neil

I will use the same Panasonic 15000UF power supply caps as mentioned in the build thread which according to Digi-Key's site are listed as 1.969" (50.00mm) in height. Guess that slim 40mm (Internal height) chassis is out of the question.

[kingnubian]

Kingnubian, other than the Sonicap Cap and Naked Vishay Resistors, are there any other parts you plan to upgrade? I'm also thinking of building a Pass B1, but I'm too lazy to read the original building thread. Maybe I'll just follow whatever you use in your build  . Please keep us posted on your progress 

So far from what I've read, changing the caps & the 4x1k resistors has the biggest impact on improving the sonics. I will, initially at least, only change those two things.

Keep in mind that even these changes ups the cost of the build significantly.

[kingnubian]

Just curious if anyone has thought of or actually implemented something like tis in their B1 build?

http://cgi.ebay.ca/Audio-Input-Selector-Relay-Board-12V-regulator-/250635746633?pt=Vintage_Electronics_R2#ht_9096wt_972

Comments?

[raindance]

To compliment my soon to arrive ClassDAudio SDS-254 I've decided that despite my newbie DIY experience I will build a Preamp to compliment the amp.
There are two paths I wish to explore in an effort to try & make a decision for this build. I have decided to look at both Passive & Tube Buffer/Preamp options.

There are a few criteria for this build:
1) Excellent sound quality (This is priority number 1!)
2) Very good quality components
3) Newbie friendly
4) Cost must be low (Under $250 CAD if possible not including case)
5) Affordable cased that actually looks like an Audio component & not a storage bin.

--Passive Preamp--:
For the Passive route from reading the forums there seems to be some pitfalls with respect to impedance matching, signal loss, ect. After reading through these & other forums here is a potential list of components that I am looking at.

--Passive Preamp--
Input selector: http://cgi.ebay.com/Input-Source-Selector-DIY-Kit-4-channels-/220651819871?pt=LH_DefaultDomain_0
Volume attenuator: http://cgi.ebay.ca/Assembled-Dale-23-Step-Attenuator-Volume-Control-10k-/270311271534?pt=LH_DefaultDomain_0#ht_2175wt_781


--Tube Buffer/Preamp--: The attenuator & Source Selector would be the same as in the Passive Setup above.
Preamp Kit 1: http://cgi.ebay.ca/6N3-5670-Tube-Buffer-Amplifier-DIY-Kit-/270472007841?pt=LH_DefaultDomain_0
Pream Kit 2:  http://cgi.ebay.ca/Complete-DIY-Kit-ref-Grounded-Grid-Pre-Amplifier-2-Ch-/270277831031?pt=LH_DefaultDomain_0

I would like comments, insights & guidance in putting together a diy preamp that sounds worlds better than it's price would indicate.

I have ordered a 6N3 / 5670 SRPP preamp "kit" from China to try with my CDA-254. It has too much gain, but I'll wrap a feedback loop (shock and horror!) around it to limit gain and post the results.

I also built a unity gain buffer using LME49710 op amps which are VERY high quality. It sounds incredibly good, but the CDA254 is limited gain-wise. You should have no trouble with the SDS model as it is already buffered. In fact my recommendation is to replace the cheap pots that come with the unit with an Alps blue dual pot and try that. Simple, and should work great. Don't get concerned with all the talk on here about gain attenuation vs volume control, as there is some confusion out there...

[kingnubian]

Just a note:
Digikey shipping, at least here in Canada, is very fast. less than 48 hours after making my order the parts have arrived via UPS.

The B1 board has been ordered from Pass Labs & now besides waiting on that (Also confirmation of my order which I haven't received yet), I'm having a little issue sourcing the Sonicaps. Seems Sonicraft is out of commission for a week or so. I got a heads up on another source and am checking that out.

[UPDATE]

Just got an answer from GR Research & they have the Sonicaps Gen 1 available! My order will be going out today.
I want to give much props to Nick77 for the hookup & all the info.

[leitmo]

i really love my Nelson Pass B1 buffer preamp, very easy to put together and no gain with impedance matching

i compared it to a system without preamp (phono pre direct to amp) and must say it sounds better with B1 preamp

[kingnubian]

i really love my Nelson Pass B1 buffer preamp, very easy to put together and no gain with impedance matching

i compared it to a system without preamp (phono pre direct to amp) and must say it sounds better with B1 preamp

I'm just waiting for my Caps (Obbligato Premiums & Russian K's) & Chassis to come in & I'll show more pics.