[Pars]

Question on CRDs. I bought some 1N5314s from a guy on diyaudio. They are marked KSI 1N5314. I tested a couple of them with my DMM in series (mA) with a 9V battery and was getting ~6.5mA thru these, which is a bit high. Any problem with using these in a sigma22 I am building? I assume you can test these in this manner also?

 

[luvdunhill]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif Question on CRDs. I bought some 1N5314s from a guy on diyaudio. They are marked KSI 1N5314. I tested a couple of them with my DMM in series (mA) with a 9V battery and was getting ~6.5mA thru these, which is a bit high. Any problem with using these in a sigma22 I am building? I assume you can test these in this manner also?

you should know by now, amb has a diagram for everything!

 

[Pars]

Yeah, I know, lazy

That's basically how I tested them just using 9V battery cuz... it was handy. Ammeter was on the other side, but shouldn't make a difference. These apparently are Knox Semiconductor (never heard of them).

 

[amb]

I use 1N5xxx series made by Central Semiconductors and they are usually pretty good. Never tried Knox, so can't comment on those.

At any rate, the σ22 will work just fine even when the CRD is that far off. In this particular application it's not the absolute accuracy that matters. As long as it's working as a reasonable CCS, then all is well.

 

[Bina]

HI, I'm thinking about building Beta 22 for my JH13.

Can you say me, how much is 2 Channel beta (this is for single ended right?)? Only price for parts for desks in beta, I will use power supply build by one of czech builder.

Thanks for response.

 

[luvdunhill]

how much gain are you planning to configure the boards with?

 

[linuxworks]

b22 for iems???


boggle!

are iems ever hard to drive? I wasn't under that impression.

why the b22 for such easy phones?

 

[IPodPJ]

With a sensitivity of 119dB @ 1mW and an impedance of 28 ohms, if you used a stepped attenuator the first notch might be too much volume. Your probably best using a potentiometer and the lowest gain setting of 2, unless you can go even lower. That's probably the most sensitive headphone/IEM in existence. Even the JH-16 is less, at 118dB.

 

[Bina]

It looks from specification, but in real, thesy need more volume than any other IEM I owned, excluding ER-4S. I dont know if this helps, but for example on Benchmark DAC 1, with bulid in amp, I set volume on something like 9 clock.

 

[luvdunhill]

Quote:

Originally Posted by IPodPJ /img/forum/go_quote.gif Your probably best using a potentiometer

I would say pretty confidentially that would be your second worst option. I'd consider a custom stepped attenuator or a DVC solution myself.

 

[tintin47]

^ yeah. I would pick the resistors for a custom stepper. Either way the beta is way overkill and unnecessary.

 

[linuxworks]

there's your concensus, a speaker-grade amp is just NOT needed (or even really wanted) to drive iems. it does not matter how much the iem's cost - they simply do not have enough mass to need anything like a b22 to drive them. you'd be defeating the purpose of a powerful amp if you 'gain it down' too much via gain and input atten.

the b22 is wrong for your app. any portable amp is fine (pimeta, mini3, etc). I would not even go to a 'home' level amp, since the portables are more than good enough for iems.

this should not be about ego or money. it should be about matching equip based on gain, impedance, power levels and need. iems don't need this kind of amp.

 

[digger945]

Quote:

Originally Posted by tintin47 /img/forum/go_quote.gif ^ yeah. I would pick the resistors for a custom stepper. Either way the beta is way overkill and unnecessary.

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif there's your concensus, a speaker-grade amp is just NOT needed (or even really wanted) to drive iems. it does not matter how much the iem's cost - they simply do not have enough mass to need anything like a b22 to drive them. you'd be defeating the purpose of a powerful amp if you 'gain it down' too much via gain and input atten. the b22 is wrong for your app. any portable amp is fine (pimeta, mini3, etc). I would not even go to a 'home' level amp, since the portables are more than good enough for iems. this should not be about ego or money. it should be about matching equip based on gain, impedance, power levels and need. iems don't need this kind of amp.

What about the unique circuit of the Beta?
What about the sound?
Ego, money, gain, impedance, power and need aside, would anything else sound the same?

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif I would say pretty confidentially that would be your second worst option. I'd consider a custom stepped attenuator or a DVC solution myself.

How about a TVC or Slagleformer?

 

[linuxworks]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif What about the unique circuit of the Beta? What about the sound? Ego, money, gain, impedance, power and need aside, would anything else sound the same?

this is my view, fwiw, but my take on the b22 is that its a great amp for driving *loads*. true hard-to-drive loads; often ones that need decent voltage swing due to the load being high-z.

iem's are not high-z and are the easiest thing to drive.

the m3 is even lower in noise than the b22 (according to amb's specs). I believe this, too; my m3 sounds slightly quieter. for iems, you want THAT!

sorry, but its just funny to imagine a humvee being used to carry bubble wrap across your backyard

it just seems that silly to me, to use a heavy duty amp to drive loads that are trivial and need no serious voltage swing.

 

[oneplustwo]

I think this is a funny debate. 99% of the population would laugh at us for amplifying headphones in the first place. I for one never even knew such a thing existed before I caught the bug myself not too long ago. So it amuses me to see 99% of us playing down the idea of using a B22 to drive IEMs.

To use linuxworks analogy, if a b22 for IEMs is like a Humvee carrying bubble wrap, perhaps a b22 for headphones like Senn HD650s is like a Humvee carrying a case of bubble wrap. Who's to say where the line should be drawn? Certainly, a Humvee carrying a load of full sized people can also be argued as excessive.

In any case, I would say go ahead and try a beta. If you enjoy the sound, then that's what matters. Every one else can offer guidance and perspective but ultimately, it's only your own personal enjoyment that matters. Worst case scenario, you sell it off and add that to your own experience. Isn't that what these hobbies are about to some degree?