Then the output DC blocking capacitor is not loaded with the 22k vol pot.
The vol pot feeds the Buffer.
The vol pot feeds the Buffer.
Considering the "2205 preamp chassis" on ebay for this B1 buffer preamp build -- what do you think? (you can just type that search string in quotes above on ebay, to see it).
It's $40 from china, full aluminum. Black top, sides and back, and silver aluminum faceplate. It's 220mm x 52mm x 191 mm (external dimensions).
Has anyone had experience with these enclosures? Worth getting? Seems like a really good price and they look nice.
It's $40 from china, full aluminum. Black top, sides and back, and silver aluminum faceplate. It's 220mm x 52mm x 191 mm (external dimensions).
Has anyone had experience with these enclosures? Worth getting? Seems like a really good price and they look nice.
try to find a pic of what the "holes" look like where the front and rear are screwed to the side panels.
Some are just a "U" shape in the aluminium extrusion, with a thread cut into the U.
A round drilled hole with a thread cut after is a far better fixing for the screws.
Some are just a "U" shape in the aluminium extrusion, with a thread cut into the U.
A round drilled hole with a thread cut after is a far better fixing for the screws.
I have this exact chassis 2205 right on my desk. I had my good buddy buy and carry over straight from China when he was there visiting. They go for about $10 US a pop plus couple bucks for domestic shipping. Kind'a like a steal.
Decent quality and good looking, but definitely nothing capable of taking abuse. Andrew has legitimate concern about the structural strength. The threaded holes on the side panel extrusion pieces for mounting the front and rear panels are indeed full threaded holes, but they are tapped into the thin material. I would allow my cat to sit on top of the case but not much more than that🙂
The top, bottom, and rear panels are all 2mm sheet work, not a problem except the rear panel feels flimsy, WILL and DOES flex when you plug/unplug cords. You would certainly want to put in some angle alu to enforce joining the real-bottom and the rear-top. You will need to drill holes and tap threads, and countersink the new holes on the top panel for flat head fasteners to go flush for good looking and not scratching the behind of a cat.
Decent quality and good looking, but definitely nothing capable of taking abuse. Andrew has legitimate concern about the structural strength. The threaded holes on the side panel extrusion pieces for mounting the front and rear panels are indeed full threaded holes, but they are tapped into the thin material. I would allow my cat to sit on top of the case but not much more than that🙂
The top, bottom, and rear panels are all 2mm sheet work, not a problem except the rear panel feels flimsy, WILL and DOES flex when you plug/unplug cords. You would certainly want to put in some angle alu to enforce joining the real-bottom and the rear-top. You will need to drill holes and tap threads, and countersink the new holes on the top panel for flat head fasteners to go flush for good looking and not scratching the behind of a cat.
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Would it be a good idea to integrate a DAC into the same enclosure as the B1 Buffer? That way the DAC is hardwired (soldered) to one of the inputs on the selector switch? i.e. bypassing the RCA's two friction connectors and length of RCA cable.
Or does a good rca cable with gold connectors connected to neutrik rca connectors not result in any loss or distortion of the signal?
Or does a good rca cable with gold connectors connected to neutrik rca connectors not result in any loss or distortion of the signal?
I´ve learn to separate the equipments: preamp and DAC in own boxes. If one equipment is fault (or not finished, in ongoing development) you can continue to use/listen with the working one.
Vishay/Dale are good, very widely available. I´ve tested all kind of resistors (AMTRANS, PRP, CADDOCK, TAKMAN...). For this application (you don´t need over 500V strength) they are like chalk and cheese.
TO92 into sockets is a very good idea, I will think about (or using MILL-MAX connectors).
Do you have a PCB for the B1?
P.S.: soldering is not a perfect interconnection on PCB, but I don´t know any press-fit semiconductor! And I´m very exasperated when I see directly soldered stranded wire on PCB!
Vishay/Dale are good, very widely available. I´ve tested all kind of resistors (AMTRANS, PRP, CADDOCK, TAKMAN...). For this application (you don´t need over 500V strength) they are like chalk and cheese.
TO92 into sockets is a very good idea, I will think about (or using MILL-MAX connectors).
Do you have a PCB for the B1?
P.S.: soldering is not a perfect interconnection on PCB, but I don´t know any press-fit semiconductor! And I´m very exasperated when I see directly soldered stranded wire on PCB!
I got the PCB and the 4 matched transistors from Pass Labs today -- looks great. I got all the resistors and all but two capacitors on order now from Digi-Key.
I just need to order 2 x 10uf Metallized Polypropylene capacitors and I'll have everything. However, I have no clue which brand and where to order -- does Digi Key have any good ones?
How about this pair from ebay? 2 Pieces Audiophiler 10uF 400V 3 MKP Metallised Polypropylene Film Capacitor | eBay
I just need a source that has a good pair in stock.. whatever brand you guys think is best I'll get. Once I have these, I'll have everything and can start on it 🙂
I just need to order 2 x 10uf Metallized Polypropylene capacitors and I'll have everything. However, I have no clue which brand and where to order -- does Digi Key have any good ones?
How about this pair from ebay? 2 Pieces Audiophiler 10uF 400V 3 MKP Metallised Polypropylene Film Capacitor | eBay
I just need a source that has a good pair in stock.. whatever brand you guys think is best I'll get. Once I have these, I'll have everything and can start on it 🙂
They should be good.
I doubt they would have relabeled an MKT, it would look too small!
Start assembly with the smallest, low profile components.
The 10uF caps will probably be the last you solder in.
Check resistor values with an ohm-meter after reading the colour coding.
Check the capacitors with a capacitance meter, if you have one.
I doubt they would have relabeled an MKT, it would look too small!
Start assembly with the smallest, low profile components.
The 10uF caps will probably be the last you solder in.
Check resistor values with an ohm-meter after reading the colour coding.
Check the capacitors with a capacitance meter, if you have one.
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Jennifer,
These are reputable merchants, in the USA, from which I have regularly purchased for over a decade. They offer different brands and grades of capacitors. Now that you have the board in hand, you can determine exactly which capacitors will fit.
The Madisound Speaker Store
Parts Express: the #1 source for audio, video & speaker building components
Zalytron
Handmade Electronics Indexpage
Thanks!
What do you guys think about Jantzen 10uf Metallized Polypropylene caps? One person that put together a parts list for B1 recommended them. I can get for around $8 each from parts express.
What do you guys think about Jantzen 10uf Metallized Polypropylene caps? One person that put together a parts list for B1 recommended them. I can get for around $8 each from parts express.
Would you really trust ebay for "audiophile" capacitors? How do we really know it is metallized polypropylene? I never heard of that seller and it doesn't really have a brand name right? I hate to spend $150 in parts on this B1 buffer and then to use a sub par critical capacitor.
If it measures as a capacitor then it is likely to be either metalised, or foil. With a 400V rating it almost certainly can't be ceramic and all the other materials used for dielectric would give a package that is far bigger.
Foil tends to be much bigger. That leaves metalised as the only feasible option.
Could it be MKT instead of MKP? That is possible but in my view unlikely.
Buy them and compare the sound to a 1uF MKP (loaded with 100k) and hear what differences are there.
Foil tends to be much bigger. That leaves metalised as the only feasible option.
Could it be MKT instead of MKP? That is possible but in my view unlikely.
Buy them and compare the sound to a 1uF MKP (loaded with 100k) and hear what differences are there.
Well maybe I should try the inexpensive route and get these Chinese caps from ebay and use my existing metal film 1/4 watt resistors I have instead of buying Vishay -- I mean the amp board I got from chipamp doesn't have the Vishay.. there must not be that much of a difference?
I could buy the other caps I need from ebay as well instead of the ones Nelson said he got (are are still readily available) from digi key.
I haven't actually submitted the order to digi key.. it's just there in the shopping cart ready for me to click order.
I could buy the other caps I need from ebay as well instead of the ones Nelson said he got (are are still readily available) from digi key.
I haven't actually submitted the order to digi key.. it's just there in the shopping cart ready for me to click order.
Any more progress on this project? I have just ordered the last of my parts to build the B1. The transistors were the last item. Found them on ebay from Alweit. Been told that they are the real ones by members here.
I made a mistake and ordered the 2 inch tall preamp chassis instead of the 3" tall one. I haven't yet ordered the 15K uf 25v electrolytic caps (x2) yet. But I know the standard size ones are 2 inches tall and they won't fit into the case I got.
Nelson Pass says the uF value isn't critical and can even be as low as 1000uF at 25V.
Do you know of a short 15K uF electrolytic that would fit on the b1 buffer board? OR a short 10k? What do you think about going smaller size?
If I have to I'll order the 3" case and just save this 2" case for another project later.
I'd order the 3" chassis if the 15K uF sounded better than a 10K uf or lower SHORT height cap.
Nelson Pass says the uF value isn't critical and can even be as low as 1000uF at 25V.
Do you know of a short 15K uF electrolytic that would fit on the b1 buffer board? OR a short 10k? What do you think about going smaller size?
If I have to I'll order the 3" case and just save this 2" case for another project later.
I'd order the 3" chassis if the 15K uF sounded better than a 10K uf or lower SHORT height cap.
These are 1.6" and should work fine. The uh is 10K which should be good enough. The schematic says 15K but it is not set in stone, it just filters the dc some more and smaller or larger could be used. There may be some shorter ones I just quickly looked not in detail.
UVR1V103MRD6 Nichicon | Mouser
UVR1V103MRD6 Nichicon | Mouser
You could actually use a 25V cap and a smaller uh and so you should find one that one work in your case. I think I just used whatever I had on hand when I built my B1 and I know it was not 15K uh and it was perfectly quiet. If you PS is quite enough the cap is not really needed, it is just insurance.
JenniferG,
Here's a 15000uF one that should fit:
SLPX153M025C7P3 Cornell Dubilier - CDE | Mouser
As wdecho mentioned, a lower value would be fine.
Cheers,
Dennis
Here's a 15000uF one that should fit:
SLPX153M025C7P3 Cornell Dubilier - CDE | Mouser
As wdecho mentioned, a lower value would be fine.
Cheers,
Dennis
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