BC184C / BC214C replacements

[BerndVP]

Hi,

I'm looking for replacement parts:
BC184C is suggested to take BC550CTA
BC214C is suggested to take BC560CTA, but can't find them so went for BC557ATA.

But I'm looking for better replacements for these types, any suggestions ?

 

[analogguru]

I bet that you will find tons of these transistors with the correct designation:
BC 550C
BC 560C

And these parts are not bad - there are only japanese parts with a different pinout.

 

[chilidawg]

Hi,

I'm looking for replacement parts:
BC184C is suggested to take BC550CTA
BC214C is suggested to take BC560CTA, but can't find them so went for BC557ATA.

But I'm looking for better replacements for these types, any suggestions ?

A, B, C is the transistor hFE classification.
TA is the factory default packaging, which in this case means taped, and BU is bulk.

 

[Whoops]

Hi,

I'm looking for replacement parts:
BC184C
But I'm looking for better replacements for these types, any suggestions ?

if you take your time to do a search on the subject around this forum you will realize that the preferred replacement for the BC184C is the MPSA18

 

[abbey road d enfer]

Hi,

I'm looking for replacement parts:
BC184C is suggested to take BC550CTA
BC214C is suggested to take BC560CTA, but can't find them so went for BC557ATA.

But I'm looking for better replacements for these types, any suggestions ?

What do you mean "better"? BC550C is better than BC184C in many respects. Higher GBW, higher Hfe, lower basespread resistance (Rbb'), higher voltage.
Generally, except noise, the actual performance of a circuit depends very little on the transistors used, since there is enough NFB to make the circuit work whichever side of tolerance they are.

 

[kr2p]

I've been looking for a BC184C for a repair I'm doing to a Neve preamp, and I've come across a uk website called dazzletech that seems to sell them new. Is there any reason that these aren't suitable? I haven't seen any mention of them on forums, which makes me a little skeptical as the general consensus seems to be to go for replacements like the MPSA18, and I'd be surprised if people hadn't come across them. The thing that makes me think that they might be legitimate is that the transistors in the (new) Neves are labelled BC184C, which means that someone must be manufacturing them with that designation, and of course they are also a uk company so perhaps these are in fact the same transistors coming from the same supplier?

 

[TheJames]

I've been looking for a BC184C for a repair I'm doing to a Neve preamp, and I've come across a uk website called dazzletech that seems to sell them new. Is there any reason that these aren't suitable? I haven't seen any mention of them on forums, which makes me a little skeptical as the general consensus seems to be to go for replacements like the MPSA18, and I'd be surprised if people hadn't come across them. The thing that makes me think that they might be legitimate is that the transistors in the (new) Neves are labelled BC184C, which means that someone must be manufacturing them with that designation, and of course they are also a uk company so perhaps these are in fact the same transistors coming from the same supplier?

If you want a BC184C transistor, lemme pull out the thousand or so MPSA18's I have, scrub off the MPSA18 label and paint on BC184C. I'll sell you all you want at $5 a pop or I'll give you a good discount if you want all of them. They'll be the highest quality BC184C's you've ever come across.

I have a AMS 1073DPX. It's loaded with prety generic looking transistors that have only a 184C marking on them. No manufacturer marking at all. They actually look like something you'd expect to see in some Chinese knock-off.

If you're repairing a Neve and need a single, or even every last 184C, I'd get whatever suitable sub I could find and move on.

 

[kr2p]

If you want a BC184C transistor, lemme pull out the thousand or so MPSA18's I have, scrub off the MPSA18 label and paint on BC184C. I'll sell you all you want at $5 a pop or I'll give you a good discount if you want all of them. They'll be the highest quality BC184C's you've ever come across.

I have a AMS 1073DPX. It's loaded with prety generic looking transistors that have only a 184C marking on them. No manufacturer marking at all. They actually look like something you'd expect to see in some Chinese knock-off.

If you're repairing a Neve and need a single, or even every last 184C, I'd get whatever suitable sub I could find and move on.

I may have miscommunicated my intentions, because I'm certainly no cork-sniffer when it comes to this sort of thing. I don't really care about the label, but I find it curious that everyone recommends MPSA18's in place of BC184C's when the latter is readily available for about the same price. As someone that hadn't heard of a BC184C until a couple of days ago, it led me to believe that not all BC184C's are created equal, and if that's true for BC184C's, then what about MPSA18's?

Normally I wouldn't give two hoots about using any suitable alternative, but since the Neve amplifier circuit works by pushing the transistors fairly hard I think my original question of "Is there any reason that these aren't suitable?" is perfectly valid. And if these things do matter (which is part of what I was trying to find out, but I suppose now that the answer is no), my guess that the dazzletech component may in fact be the exact replacement part makes everything a lot simpler for someone like me who doesn't know what's good and bad. I'm just trying to figure out what's what!

 

[TheJames]

I may have miscommunicated my intentions, because I'm certainly no cork-sniffer when it comes to this sort of thing. I don't really care about the label, but I find it curious that everyone recommends MPSA18's in place of BC184C's when the latter is readily available for about the same price. As someone that hadn't heard of a BC184C until a couple of days ago, it led me to believe that not all BC184C's are created equal, and if that's true for BC184C's, then what about MPSA18's?

Normally I wouldn't give two hoots about using any suitable alternative, but since the Neve amplifier circuit works by pushing the transistors fairly hard I think my original question of "Is there any reason that these aren't suitable?" is perfectly valid. And if these things do matter (which is part of what I was trying to find out, but I suppose now that the answer is no), my guess that the dazzletech component may in fact be the exact replacement part makes everything a lot simpler for someone like me who doesn't know what's good and bad. I'm just trying to figure out what's what!

I think my point was perhaps missed. Dazzletech does not look like a semiconductor fabricator, but rather an importer and reseller of electronics parts and goods.

Parts manufacturers often offer "house-labeled" runs of their parts. So for instance, I could contact Texas Instruments and say I want 10,000 of their 5532 opamps, but instead of 5532, I want them marked JG5001. They would come back with a quote, I'd pay the fee, and in a few weeks boxes of JG5001 chips would show up at my shop.

If Dazzletech has parts listed as BC184C's, I feel confident in saying that they are actually another transistor type but labeled as a BC184C. Either that, or they put in a massive order for real BC184C transistors when the "last call" was made by the original fab.

 

[dmp]

It was only a few years ago that BC184c were discontinued. You could buy them for a few cents before that. I bought a box as they were being discountinued knowing they were going away - it's not surprising that there are NOS stockpiles around and being sold. But like all the other extinct chips, as the price goes up the possibility of fakes increases.
I had a bad bunch of bc184 also, back before they were discontinued. Bought new from Mouser and created a pocorn kind of noise in a 1084 build.
I also think BC 550C, BC 560C are fine substitutes that you would not be able to here a difference from a good bc184c.
Maybe only seek out bc184c for restorations if it is important to you.

 

[JohnRoberts]

Learn how to read device data sheets. Of course the application matters too. Compare old device specs to proposed replacement device.

In general the most important specification is proper polarity (NPN or PNP). Next is breakdown voltage. For high power applications current matters too.

For low noise stages ein or NF matters, and some low noise devices are graded for beta (current gain).

Better is usually better but if the spec is better than needed it could be wasting money.

JR

 

[nielsk]

It is nice if the pinout is the same. MPSA18 is opposite, BC550(C) is the same.

 

[Whoops]

For sure there is stock left of BC184C in wharehouses around the world so a store might be selling old stock, I don’t think that demand of BC184C is high enough that would be an item worth of faking or counterfeiting…
As far as I know only people looking to DIY some Neve circuits will search for them, and not that it’s a special transistor it's just that at some point Neve used them, but Neve also used BC107 and BC109 a lot before using the BC184C.

I don’t see any reason for not using BC560C or MPSA18.
The MPSA18 has consistently high HFE so it might give a better noise figure than the BC184C

use whatever you can get and move on an record some music with it, have fun

 

[CJ]

Suffering through OPS (Obsolete Part Syndrome) is all we do here at GroupDIY.
For me it is while working on Marantz stuff.
Obviously you want the same sound, you hope for more dependability from a newer part and you want it cheap and to hopefully have the same pinout so you do not blow something else up.
Tall order. Usually a compromise.
What to do?

First thing is pull up a datasheet.

Power rating should be the same or a bit higher.
Vceo voltage need not be a perfect match, you can use the same voltage or higher.

Collector current rating should be the same or higher, but to a limit. You do not want a transistor with 1 amp collector current replacing a 40 ma transistor.

For one thing, the package will most likely be bigger.
Second, the sound might change.

Then you have gain. If there is negative feedback involved, then having the exact gain transistor might not be necessary.
You may want to match gain if using more than one transistor, such as in a differential pair. Once again, this will probably depend on the exact circuit being used. I like to match diff pairs no matter what, that way i do not worry about it. And it keeps the left and right channels on a stereo matched up unless the dual volume pot is off, which it usually is.
And as mentioned, watch out for the "a,b,c" thing after the part number as it can designate gain.

Last thing to worry about is frequency response.
Propeller heads call this Current gain bandwidth , switching time, slew rate, etc.
If the new part is too fast, you might have amplifier stability problems.
You can compensate for this if you know how, usually it involves the placement of small capacitors in a way that will not cause more problems,

Noise is also a consideration. That is the usually the best thing about using a modern replacement, you get a better noise figure.
A number for noise is not always given on the data sheet, it might be mentioned in the description of the part.
This is where an online forum can be useful. people who have gone through the same thing can steer you to a low noise part.

For the Marantz stuff we use a lot of KSC and KSA parts, like KSC 1845 and KSA 1015 as they have a rep for low noise and good sound.
You can find your own match by going to the DigiKey website and picking the parameters off the search engine.

Some audio pieces garner more attention when it comes to choosing parts, probably one of the best examples of this is the UREI 1176 compressor. We have had a couple of bar room brawls over a stash of Toshiba 2SK170's, jus kiddin.

 

[CJ]

here is another data sheet that has a noise figure>

 

[CJ]

if you can, determine the current that the transistor handles, as this can be used to better match up gain-hfe.
Hfe can change quite a bit at different current levels.

here is a BC184C sheet that has noise and the gain for the C series>

 

[CJ]

so if i was transistor hunting, i might do something like this:

write down the original specs at the top of the page, go to digikey search, program in specs, pick some out,

if i was a pro engineer i would ditch the MPSA18 to cover my bacon as it is only rated to 100ma collector current, 1/5th the BC184C rating, and the gain looks to be too high. sure, it might work if the circuit does not get near 100ma, but it don't look good in court or the board room meeting.

i like the KSC 1008 for the 50 M Hz spec.

a few of the K numbered transistors have an option to buy 3 gain ratings.
you could buy all 3 as they are pennies a piece, then fit them to the circuit and measure performance against identical unit, and/or match the voltage on the collector.

stuff i would try circled in blue>

 

[Whoops]

MPSA18 is a great replacement for BC184C in Neve circuits, the HFE being 600 or higher helps a little bit the noise figures specially the ones used in first in the input stages.
That’s what I and a lot of people use for Neve circuits and works great.

That’s my recommendation

But thank you so much CJ for your input and for explaining a good method to follow when choosing replacement transistors

 

[iprovlek]

BC107C,BC109C,BC547C,BC550C.... for BC184C

BC560C and BC557C for BC214C

 

[jokeramik]

Hello,

the test conditions for NF are different between MPSA 18 and BC 184. So you must adjust the collector current.
Best regards!
jokeramik