I looked at the parts for the Bijou amp on
https://www.cavalliaudio.com/diy/bijou/main.php?page=ampparts
and was wondering whether the cheaper resistors with around 100ppm (Temperature Coefficient) will do or if they should be 10ppm or at least 50ppm ? Does it really matter with regards to sound/reliability ? Thanks.
https://www.cavalliaudio.com/diy/bijou/main.php?page=ampparts
and was wondering whether the cheaper resistors with around 100ppm (Temperature Coefficient) will do or if they should be 10ppm or at least 50ppm ? Does it really matter with regards to sound/reliability ? Thanks.
For this circuit 100 ppm or even more is not a problem. And for the most part 1% is not necessary either. Personally I never liked or used ⅛ watt resistors. They're too damn small and hard to work with, meaning fragile. ¼ watt is the smallest I use. And metal resistors don't like overloads. But that's another whole discussion.
Specifying 1/8W resistors for a valve design is daft. At the first DC fault half your resistors go up in smoke; then how do you do fault tracing? 1/4W minimum, but 1/2W would be better.
Temperature coefficient is irrelevant. Almost all modern resistors are much better than those which were routinely used in the valve era.
Temperature coefficient is irrelevant. Almost all modern resistors are much better than those which were routinely used in the valve era.
Bijou parts (capacitors)
I'm going through the parts list for the Bijou and it (among others) lists the following two capacitors:
Metalized Polyester/Polypropylene Film 100n 400V
Metalized Polyester/Polypropylene Film 1u 250V
I looked at mouser.com and seem to have difficulty finding the right one (sorry, newbie issue). Anybody got a link?
Does the 400V or 250V refer to AC or DC voltage?
Thanks for the help.
I'm going through the parts list for the Bijou and it (among others) lists the following two capacitors:
Metalized Polyester/Polypropylene Film 100n 400V
Metalized Polyester/Polypropylene Film 1u 250V
I looked at mouser.com and seem to have difficulty finding the right one (sorry, newbie issue). Anybody got a link?
Does the 400V or 250V refer to AC or DC voltage?
Thanks for the help.
The marked voltage is always DC (or peak) unless specifically marked AC.
The outer foil is often marked with a line.
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Bijou transformer
I am still going through the list of parts for the Bijou amp and started looking at the transformer. It lists the Hammond 270 DAX (117 VAC ; 6.3V at 3.5A) as the recommendation. I read some places, though, that EdCor got some cheaper ones. Anybody know their equivalent (model number) and maybe reasons why using one of those might be a bad idea?
I was also wondering if there is any sound improvement in getting two and running each channel separately (as a mono block, so to say) ?
I am still going through the list of parts for the Bijou amp and started looking at the transformer. It lists the Hammond 270 DAX (117 VAC ; 6.3V at 3.5A) as the recommendation. I read some places, though, that EdCor got some cheaper ones. Anybody know their equivalent (model number) and maybe reasons why using one of those might be a bad idea?
I was also wondering if there is any sound improvement in getting two and running each channel separately (as a mono block, so to say) ?
Edcor makes good transformers for the money. The only problem is they make them when you place your order so for me it is usually about 8 weeks wait time.
I have noticed that you have multiple threads for just this one amplifier. It might be less confusing to people if you had just one thread dedicated to this amplifier. Maybe mods can tidy it up into one thread? Anyway I have had good luck with Edcor transformers.
I have noticed that you have multiple threads for just this one amplifier. It might be less confusing to people if you had just one thread dedicated to this amplifier. Maybe mods can tidy it up into one thread? Anyway I have had good luck with Edcor transformers.
8 weeks ?!? Wow... they don't have any "standard" models available to ship out? Is there even a model then or do you have to tell them what you need and they build it for you? (that by itself sounds expensive). Sorry about the multiple threads btw. You got a point
How much cheaper than $59.63 + shipping do you need? the Hammond 270DAX is pretty capable… 50 Hz ÷ 60 Hz, 117 V input, 76 VA, 520 VAC center tapped, 6.3 VAC at 3.5 amps. It presumes solid-state rectification.
Edcor … will take 8 weeks? The XPWR001 (which is roughly equivalent) is $46. You save $10 bucks. Mmmm… maybe I'm jaded, but if my budget were that tight, I don't think I'd even be doing the project. Heck, I can barely go out for lunch these days and get change back from a ten dollar bill.
GoatGuy
Edcor … will take 8 weeks? The XPWR001 (which is roughly equivalent) is $46. You save $10 bucks. Mmmm… maybe I'm jaded, but if my budget were that tight, I don't think I'd even be doing the project. Heck, I can barely go out for lunch these days and get change back from a ten dollar bill.
GoatGuy
I thought $5.00, including tax, would be reasonable
I guess that's just what it costs, right. For some reason it makes me feel bad, though, to spend such an amount on a transformer, if it were the tubes, etc. I would probably think "ooh... its directly for the sound, so whatever..." but the transformer always feels like it's only for turning the whole thing on/off. Well, it's a longer project anyway and I know what you mean, living in the SF bay area half my income goes straight to rent, so you got to save where you can....which get's difficult when you can't even contain your wife's spending
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