Blue cactus question

[Gus]

Does anyone one have one. The reason I ask is because I believe it uses Blues version of the kk47. The blue cactus capsule sells for about $400.00 last time I looked thats not too bad a price if the capsule is good.

I am thinking of a um900 grill with the blue capsule for a new microphone build. Any feedback on the capsule sound would be nice.

Seth likes his 900 thats why this post.

 

[Jazzy_Pidjay]

http://www.groupdiy.com/index.php?topic=3876&start=0&postdays=0&postorder=asc&highlight=

any questions ?

i haven't sound clips, the G7 "cactus" is at my friend home.

 

[audiovisceral]

what i don't understand is how you get the capsules all by themselves. call blue direct, lie and say it's for repair? what if they want your s/n, or tell you to send it to them? i'd like two blue cactuses if i were going ahead ...

 

[Gus]

Look at the date of the posts.

 

[audiovisceral]

[quote author="Gus"]Look at the date of the posts.[/quote]

i'm aware. i saw no reason to start a new thread.

also to add to the question. i notice peluso has a 47 too now. thoughts?

http://canadianaudiodistributors.com/Index/PK47.htm

 

[kato]

Blue used to sell just the unmounted capsules.

There was a link on their site labeled "Raw Capsules" where they sold raw capsules for the Kiwi (U87), Cactus(U47), and Plum (U67).

I can't find them on their site today but you could buy them direct at the time of the original post.

They were $400 ea.

 

[Skylar]

I have a Cactus.

This mic is extremely dark. Before purchasing, I had read a lot of folks' comments on the mic--everyone seemed to agree about its darkness.

I thought "ahhh, these people are just accustomed to modern, super-bright LDCs; it's probably not THAT dark."

Well, they were right--it's pretty damn dark.

I love it, but I imagine the Cactus may not be bright enough for some people's tastes.

I've gotten some ultra-smooth vocals from this mic through an SCA n72 pre.
I tend to use this mic for instruments that I need the highs to be smoothed (i.e. trumpet/flugelhorn).
...not sure how I feel about it on acoustic guitar--I still need to experiment with more patterns to find the optimal fit for my environment + my acoustic guitar, which is kind of dark also (Martin D-35).

It seems that Blue has made several, dramatic revisions to the amp on this mic. It's possible that they may have made changes to the capsule as well over the years--this is purely speculation based on the amp changes: see pictures.


From the Cactus owner's manual (earliest Cactus design?):



My Cactus (made before all the BLUE vs. VIOLET madness):



Newest revision (post-VIOLET split?):



Here's a couple more photos; if you guys wanna see more of the guts, let me know. I don't have a picture of the capsule though--I'm kinda scared about taking the grill off!

 

[Gus]

Thanks for the pictures Looks like good parts in all of them

First two look like russian tubes. I like the tubes I heard in 19a19s and 19a4s. I wonder if they are the same number. Last version tube I need to look at some tubes to see if I can match it. I wonder what is going on with the two transistors?

First looks like a EI transformer yours looks like a U can't tell if it has a I lam part the last picture looks like U

If you are up for it what are the plate and cathode resistors values? I would guess 100k and maybe 3.9K. 25 to 30VDC at the plate?

I have not heard a cactus does it have that nice low end a 19a19 has?

The picture at the Blue site years ago looked like a k47 capsule IIRC.

 

[kato]

Great pictures!

Let us know how this project goes!

 

[Sonic]

All greetings!
On LOMO 19a-19 there is a triode 6с6б (6s6b) or 6с31б (6s31b). On the top two laid out pictures there is a pentode 6ж1б-вр (6j1b-vr), and on a following picture the triode of type 6н23п (ECC88)/6н2п (ECC83).

 

[audiovisceral]

great info guys. i'll go with peluso c12/k47. affordable and well-liked from what i hear.

 

[Gus]

Sonic

Thanks for the tube numbers I could not read them on my crt.

 

[Skylar]

[Just reporting back...bringing a dead thread back to life.]


Gus,

You are very close, not surprisingly.

plate resistor = 130K
cathode resistor = 3K

I measure 57VDC at the plate.

The transformer looks like it's made up of alternatingly stacked U lams. (I forgot what this is called—someone jog my memory)

The remote pattern voltages vary from 0V (omni) to 35V (cardioid) to 70VDC (figure-of-8).

 

[Gus]

Slylar
You might want to try this circuit in the body you are working on as a circuit to use in it, try to find the Russian tube.  I would use a different transformer design.

http://www.magmet.com/lamination/duindex.php

 

[stitch-o]

My Cactus (made before all the BLUE vs. VIOLET madness):

Is that K73 a russian teflon cap in your cactus?
That's not stock is it????
Have you played with other types?

 

[Skylar]

It's the stock capacitor.

A google search points to "K73-11" being a Metallized Polyethylene Terephalate or PET film cap.
I believe that would make it Mylar, correct?

Anyway, it sounds great. I don't really have any intentions of swapping it in this mic.

I am going to take Gus' advice and build one of these, so I'll check out other options when the time comes.
I was able to get 20 of these tubes at a 60¢ a pop.

 

[stitch-o]

Firstly, sorry to sidetrack with my personal questions:

It's the stock capacitor.

A google search points to "K73-11" being a Metallized Polyethylene Terephalate or PET film cap.
I believe that would make it Mylar, correct?

"They are all the same. Mylar is the trade name used by DuPont."
http://www.diyaudio.com/forums/parts/143675-petp-capacitors-one-best-2.html

Interesting...

 

[saint gillis]

Anyone knows the PSU voltages? B+ and heater..?

 

[Van Zupa]

Hello there!

Skylar what PSU do you have? is it the 9610 or the other "Cactus" PSU? Have you tried to use a modern BOTTLE / CACTUS PSU with this mic? I have 4 of the same as you have in mint condition - old factory stock but no PSU and since they are very hard to come buy I would like to be certain before I buy one. If it is possible please send me a photo of your PSU to [email protected] manyu thanks​