JLM Baby Animal

[rodabod]

The other thing to consider here is the share of gain for a given fixed amount of gain from the preamp. Ie. the opamp will be working harder for a fixed amount of gain, if you use a lower ratio transformer, as the transformer will be providing a lower portion of the total gain.

This might be worth considering if you want to really drive your discrete opamps, or if you don't.

Also, the noise figure should be different when using different ratios.

 

[Purusha]

I don't use any ribbons for now. So the best way is to try and see what happens with either option :grin:

 

[Greg]

[quote author="Purusha"]I don't use any ribbons for now.[/quote]
Get some !!! :green: They'll change your life... I love them on guitars.

 

[Purusha]

I am planning to get a Beyer M160 specially for that purpose, just a little short with $$$. DIY has sucked all my savings

 

[ruairioflaherty]

Hi Purusha,

do some research on ribbons before you pull the trigger. Ribbons are one of the current hot tickets on on the forums guaranteed to make your tracks better.....lotsa hype

I had a Beyer 160 that I bought new and I thought it was awful (particularly on electric), the only thing I liked it on was strings but I have lots of mics to cover that anyhow. I sold it and never miss it.

Now Royers are a whole nuther thing,

Ruairi

 

[rodabod]

You didn't like the M160??? :shock:

Was it working ok?

Strange.....

If you are looking for a nice ribbon, check out Beyer, Royer, Coles and Crowley & Tripp.

You might want to try a Beyer M260 too...

 

[Purusha]

Hmm, didn't know this. Thanks for the tip :thumb: I like the M130 for the OH and classical guitars though. I just heard that the ribbons rock on the cabinets too.

I heard about Royers, but they are also twice the price if I remember. Any suggestion for the top notch new metal guitars?

 

[Purusha]

You might want to try a Beyer M260 too...

I know we are off topic here... but isn't a M260 a dynamic mic?

 

[rodabod]

[quote author="Purusha"]
I know we are off topic here... but isn't a M260 a dynamic mic?[/quote]

No, it is a single-ribbon microphone. It has a big proximity effect and can sound very nice. The M160 is probably more realistic, and has a better high-end response.

For metal guitar, I like the Sennheiser MD421 and the Beyer Soundstar X1N.

 

[rodabod]

[quote author="Purusha"]isn't a M260 a dynamic mic?[/quote]

Oh, and all ribbon microphones are dynamics - there are moving coil dynamics, and ribbon dynamics. :thumb:

 

[Purusha]

Thanks Rod :thumb:

 

[bluezplaya]

I have just completed my JLM BA 4 channel pre. Everything works fantastic! I ordered the front panel from Joe and drilled it out myself. I'm really pleased with the outcome of everything. I will be posting pictures very soon! :green:

I have a total of 6 and will be putting the other two in another chassis identical to the first. One problem I noticed with one of the boards was there is no audio signal at all, just hiss. The hiss is coming from the output when I plug a 1/4" cable to it into the recorder.

I swapped the opamps around to other boards and they are fine. I swapped and double checked my wiring and they were wired up correctly.

Has anyone experienced this problem with there boards?

Adam
:sam: :sam: :sam:

 

[mattmoogus]

Did you fit the jumpers on that channel if theres no DI? Thats a common thing to miss. Also check the voltages on that channel to ensure power is getting to the right places. Sounds like youve missed some jumpers though.


M@

 

[bluezplaya]

Actually, this particular pre (Channel 2) was connected to the DI but I disconnected the DI and tried it with the jumpers as well and the same old hiss.

I will check voltages.

Thanks,
Adam
:sam:

 

[mattmoogus]

Also check the transformer wiring (if its a 1:4) and that there isnt extra solder thats run down the legs (if its an OEP) and shorted anything out. If you run signal into it (from a cd player with the pad in) you should be able to trace the signal through the pre by touching the tip of a TRS jack onto joints on the board. This way you can see where the signal is getting to and then find the break.


M@

 

[Schmilsson]

Something is very wrong, or at least I'm measuring very wrong. :wink:

yellow/blue = 2,17v
red/green = 0v/4,18v
+v = 4,34v

 

[mattmoogus]

Have you checked the 10ohm resistors?



M@

 

[Schmilsson]

yup, they're fine

 

[mattmoogus]

Are you getting 48V on both sides of the 10ohms?


M@

 

[Schmilsson]

nope 4,35v