Sweet Sounds on the cheap Preamp Build

kingnubian · « **on:** 26 Aug 2010, 05:45 pm »

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.

ebag4 · « **Reply #1 on:** 26 Aug 2010, 05:51 pm »

I am running a Dodd DIY Preamp in front of my ClassD amp, it is fantastic. In my opinion it is a no brainer, especially given the low price of admission. It was a pretty easy build as well with pictoral instructions on Garys site. I love mine!

Good luck!

Best,
Ed

Edit: Whoops, I didn't see the cost requirement, I think the Dodd would be a bit more than that depending on the case and volume control options you choose. Plus you need to come up with a battery and a charger, sorry about that chief!

roymail · « **Reply #2 on:** 26 Aug 2010, 06:12 pm »

Pass B1 buffer/preamp
or
Dodd buffer/preamp

Nick77 · « **Reply #3 on:** 26 Aug 2010, 06:22 pm »

Quote from: roymail on 26 Aug 2010, 06:12 pm

Pass B1 buffer/preamp
or
Dodd buffer/preamp

I second the Pass B1, i am running one with the ClassD amp and makes a great combo. The cost of admission is also low depending on case and parts. Their is also a tutorial in the lab section thanks to Wushilui.

toxteth ogrady · « **Reply #4 on:** 26 Aug 2010, 06:25 pm »

As an alternative to a buffer you may want to look into LDR-based volume controls like the Lightspeed or Lighter Note. I know of one guy who preferred the Lighter Note to the Pass B1 for his classdaudio amp. I'm building both and will share my comments when I've had ample time to compare.

chlorofille · « **Reply #5 on:** 26 Aug 2010, 07:08 pm »

Oatley Electronics K272A preamp/headphone amplifier. An amazing value at $30. You can roll Op-amps to custom tune the sound. HEre is my build ...

wushuliu · « **Reply #6 on:** 26 Aug 2010, 09:25 pm »

Quote from: chlorofille on 26 Aug 2010, 07:08 pm

Oatley Electronics K272A preamp/headphone amplifier. An amazing value at $30. You can roll Op-amps to custom tune the sound. HEre is my build ...

I built one of those. Had some grounding/hum issues (my fault I'm sure, not the board). This was before the B1. Really did sound very good.

julcat · « **Reply #7 on:** 27 Aug 2010, 01:54 am »

Does anybody knows if there is some place with a complete B1 Kit?????

kingnubian · « **Reply #8 on:** 27 Aug 2010, 04:26 am »

Quote from: julcat on 27 Aug 2010, 01:54 am

Does anybody knows if there is some place with a complete B1 Kit?????

I'm interested in this as well or if not available a good quality diy kit.

chlorofille · « **Reply #9 on:** 27 Aug 2010, 04:40 am »

There are a few kits on ebay you could check out. The tube buffer + preamp sold by Arjen Helder is supposed to take out the sharpness/edge of tripath based amplifiers. ANyway here are the links :

1. Arjen Helder's integrated tube buffer+preamp
2. Jim's audio B1 Kit

1st option comes fully built with tube included. All you need is a 12V battery or a regulated supply ranging from 11.5 - 14V.

I received Arjen's tube preamp yesterday, so if anyone is interested, I could provide a comparison of that vs Oatley preamp.

bigjppop · « **Reply #10 on:** 27 Aug 2010, 04:49 am »

I think the Bottlehead Quickie would be perfect for what you're after. They have a great forum as well that is very helpful.

www.bottlehead.com

Check em out.

wushuliu · « **Reply #11 on:** 27 Aug 2010, 05:05 am »

Quote from: julcat on 27 Aug 2010, 01:54 am

Does anybody knows if there is some place with a complete B1 Kit?????

Well I have an assembled DCB1 for sale in the Trading Post. Just need to an enclosure, RCAs, etc. Can't beat that for the money.

kingnubian · « **Reply #12 on:** 27 Aug 2010, 05:10 am »

Quote from: chlorofille on 27 Aug 2010, 04:40 am

There are a few kits on ebay you could check out. The tube buffer + preamp sold by Arjen Helder is supposed to take out the sharpness/edge of tripath based amplifiers. ANyway here are the links :

1. Arjen Helder's integrated tube buffer+preamp
2. Jim's audio B1 Kit

1st option comes fully built with tube included. All you need is a 12V battery or a regulated supply ranging from 11.5 - 14V.

I received Arjen's tube preamp yesterday, so if anyone is interested, I could provide a comparison of that vs Oatley preamp.

Firstly, I'm really liking the Audio Circle forums & community. The response has been great!

The Pass B1 seems like what many are talking about & I went to this thread (http://www.audiocircle.com/index.php?topic=78312.0) with great interest. How dies the kit that you linked to on Ebay compare sonically & quality wise to just ordering the PCB from Pass directly & going shopping for the parts?

How does all this compare to the Tube preamp you also linked to?

kingnubian · « **Reply #13 on:** 27 Aug 2010, 05:11 am »

Quote from: bigjppop on 27 Aug 2010, 04:49 am

I think the Bottlehead Quickie would be perfect for what you're after. They have a great forum as well that is very helpful.

www.bottlehead.com

Check em out.

Very interesting. Looks like something I will definitely look to for another project I'm planning.

JohnR · « **Reply #14 on:** 27 Aug 2010, 05:46 am »

You could just use a switch for source selection instead of the relay board - save having to provide it with its own power supply.

chlorofille · « **Reply #15 on:** 27 Aug 2010, 06:25 am »

Quote from: kingnubian on 27 Aug 2010, 05:10 am

How does all this compare to the Tube preamp you also linked to?

Hi,
Pass B1 is very good, provided that you don't need any gain or want a ultra neutral presentation. I simply went for the Arjen Buffer because it consists of a buffer and preamp stage; and I like my music coloured slightly with the rich valve tone. I have it playing now and the sound is effortless. Mostly due to perfect matching of gain. My amp is Aussie amplifier Nxv200.

My Oatley preamp has a more forward midrange and a weaker bass but throws a wider soundstage. It is all a compromise.

kingnubian · « **Reply #16 on:** 27 Aug 2010, 12:30 pm »

I'm stoked for a B1 build. This thread is an excellent source of info & pretty much told me most of what I need.
http://www.audiocircle.com/index.php?topic=78312.0

I have a question though. With respect to the parts selection, would I get improvement sonically if for example I went with this cap (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=027-244) over the one listed in the thread (http://www.parts-express.com/pe/pshowdetl.cfm?PartNumber=027-932&DID=7) ?

If so what other reasonable priced changes can I make to get the absolutely most out of this build?

walkern · « **Reply #17 on:** 27 Aug 2010, 10:36 pm »

The 4 X 1K signal resistors can be upgraded without breaking the bank, and the reports are that doing so nets out a nice improvement in sound quality. Also, some of us have set up battery power systems rather than using the wall wart power supply, with improved sound quality as well, and this can be done for anywhere between $30 and $50. Even though it's lengthy, I'd recommend you read the whole "Nelson Pass B-1 Preamp Build" thread elsewhere in The Lab section for more sound advice from fellow B1 enthusiasts.

Neil

kingnubian · « **Reply #18 on:** 27 Aug 2010, 11:17 pm »

Quote from: walkern on 27 Aug 2010, 10:36 pm

The 4 X 1K signal resistors can be upgraded without breaking the bank, and the reports are that doing so nets out a nice improvement in sound quality. Also, some of us have set up battery power systems rather than using the wall wart power supply, with improved sound quality as well, and this can be done for anywhere between $30 and $50. Even though it's lengthy, I'd recommend you read the whole "Nelson Pass B-1 Preamp Build" thread elsewhere in The Lab section for more sound advice from fellow B1 enthusiasts.

Neil

Thanks for the response. I have skimmed through the whole thread & will do so again when time permits. Are there any suggestions for component changes like what you have stated that can be put in point form in this thread?

wushuliu · « **Reply #19 on:** 28 Aug 2010, 12:27 am »

Quote from: kingnubian on 27 Aug 2010, 11:17 pm

Thanks for the response. I have skimmed through the whole thread & will do so again when time permits. Are there any suggestions for component changes like what you have stated that can be put in point form in this thread?

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+?...