Passive EQ + GSSL. Great 2-buss insert!

[Tillmann]

That is a nice little arrangement! She's got a beautiful voice.

a
z

 

[Luny Tune]

[quote author="Brad McGowan"]I'm assuming that the resistor change that was made to the circuit when adding output transformers is the same regardless of the make of transformer used? Is that a correct assumption?[/quote]
Sorry, Brad. I forgot to answer your question. Yes, regardless of the make of trannies you should change the four 100 Ohm resistors in the output section with 22 Ohm ones. I think that Jakob recommends resistors under 47 Ohm in his latest revision of the pdf file with schematics and pcb layouts. He suggested 22 Ohm resistors to me though. Maybe it's because we were trying to fit OEPs in there whereas the Lundahls are easier driven and thus don't need as much current. The Lundahls would probably work just fine with 47 Ohm resistors... Dunno! I'm really just guessing here... :wink:

 

[Luny Tune]

I just modified it a bit. I am using the GSSLs Makeup Gain as a gain stadge for the passive eq and that wirked fine with the GSSLs low threshold. However to have almost unity gain through the mackine I had to crank it up full. Sadly, but to be expected, that sort of raises the noisefloor just about 20 dB and that IS audible!

I toyed with the idea of putting a simple line amp between the eq outpt and the GSSL input, but again J.E. assisted with a very simple solution. Changing the four 22K input resistors (right after the input caps) in the GSSL input stage to 4K7 resistors I'm almost back to unity gain through the machine. J.E. suggested that I might gain about 12 dB but it turned out to be right on the money!

So anyone building this monster for them selves; You should change those resistors to 4K7 Ohm resistors. :grin:

 

[syn]

Great idea, great all...BTW i like lundahl+OEP version...More life, more sound at least on KRK7000B...I'll be building G-SSL soon and will absolutely stick some transformers in it...It is subtle but music and sound are about subtle things IMHO...

cheerz

m

 

[Purusha]

Just curious, I will put two Lundahl transformers on the input of my Dual Pultec. Is the LL5402 the best option? This one is not so expensive as others so I have my doubts. I noticed that most of Lundahl transformer cost around 50? but LL5402 costs around 38? only.

 

[jensenmann]

LL5402 is the right one. I guess it´s cheaper since there are less windings inside (copperprice!) :roll:

 

[Greg]

Lundahl is good shit, man

I'm putting one on the output of my Forssell Opto Compressor... bam!

 

[Purusha]

Hi Greg,

I heard that Lundahls are very clean and don't do much coloring. If this is true than what is the benefit by putting them in the circuit?

 

[enthalpystudios]

ya know, i've wondered the same thing.

but i have some lundahls that have not yet been inserted into a circuit, so I don't really have room to talk as I sit here not trying anything for myself with my own ears.

but yeah, i've wondered the same.... but hey, i guess color is 'theoretically' a bad thing, saturation, harmonic distortion, LF saturation/distortion, high frequency problems with leakage inductance and winding capacitance cuasing phase issues at high frequencies....

i suppose a lack of 'color' would be 'theoretically' good

but thats what they say about digital. and i dont really but that one.

i dont know squat tho, i'm just learning at all this

what is the deal with lundahl's anyway? they're small, but have tons of low end.... is it some departure from normal transformer practices? really smart interleaving on the winding? insulation from winding capacitance?

maybe sir cj has thoughts

billy

 

[jensenmann]

[quote author="Purusha"]Hi Greg,

I heard that Lundahls are very clean and don't do much coloring. If this is true than what is the benefit by putting them in the circuit?[/quote]

Debalancing the signal. If you use your circuit in an unbalanced environment you can omit the iron.

 

[BradM]

I like what the Lundahl does to the high and low end of the mix. It's subtle but very musical. I'm getting ready to build my own GSSL and will be putting Cinemag CMOQ-2L (50/50 nickel/steel) transformers on the outputs. This should give me some really nice color while still maintaining good bandwidth and frequency response.

Brad

 

[Luny Tune]

Precisely! It's not only about color, but also about the right conditions for the transformer to perform well, i.e. with good bandwidth and so on. And the Lundahls DO color the signal. The reason why OEPs perform as well Lundahls (in my opinion) in the output of the GSSL is that the right conditions are there.

Sometimes the Lundahls perform very well in conditions where the OEPs would not (and still with the kind of coloration that we like) and sometimes conditions are such that the OEPs perform just as well as the Lundahls.

And then there's the grey area where some prefer the coloration of the OEPs better than the Lundahls or vice versa.

As I understand it the OEPs need more current than the Lundahls to give us the kind of sound that many of os love.

 

[Greg]

Purusha:

As others have stated, transformers do more than just color the sound...

Just to name a couple, they balance and deblance our units, and provide isolation from the outside world. They provide "loading" in our circuits. For example, mic transformers load the microphone, and output transformers load our output stage...

The best way to get a feel for Lundahls, or the "sound" of any transformer, is to try one out. It's very difficult to describe "color," or lack thereof. And have no worries, if you don't feel it fits well in your circuit, I'm sure you'll be able to find a buyer around here.

 

[Purusha]

Great, I'll order a few then :wink:

 

[Purusha]

[quote author="Luny Tune"] Yes, regardless of the make of trannies you should change the four 100 Ohm resistors in the output section with 22 Ohm ones. I think that Jakob recommends resistors under 47 Ohm in his latest revision of the pdf file with schematics and pcb layouts. He suggested 22 Ohm resistors to me though. Maybe it's because we were trying to fit OEPs in there whereas the Lundahls are easier driven and thus don't need as much current. The Lundahls would probably work just fine with 47 Ohm resistors... Dunno! I'm really just guessing here... :wink:[/quote]

Would 22Ohm resistors be better also for no tranny G-SSL or only when OEPs are on the output?

 

[gyraf]

..Only when driving transformers..

 

[Purusha]

Thanks Jacob. :thumb:

 

[tommypiper]

[quote author="mattmoogus"]... I vastly prefer the transformerless mix....
M@[/quote]

To my ears the transformerless mix had much more high mid and high end energy and I agree with Matt about the differences. The extra crispness may not be the right approach for this song, probably not, but the sound is quite different than with the input and OEP output transformers. The vinyl crackle is snappier, the subtle scratchiness in the voice comes through the mix much clearer, everything is separated more and apparent without the OEP transformers.

The input and OEP out mix sounds are glued together and even sound a bit smeary to my ear.

The Lundahl outputs have a similar clarity to the no transformer mix and come close to the transformerless mix, but the transformerless sample is the clearest to my ear. However, I like the low end best with the Lundahl outs. It's happening! It seems to be the best solution for my ears.

 

[synthi]

Hi Luny,
I really like your idea of using that pàssive eq in front of the GSSL.

I`m thinking in a passive eq circuit like yours, but for use in front of a mic preamp so I can add different sound characters depending on the micpre I use.
Whats the output impedance for your circuit? would be easy change the output impedance to be suitable with micpres (if its too high)?

Thanks!! :thumb:

Synthi

 

[Coldsnow]

Probably a dumb question but I just want to make sure. The 33n is the 20h frquency and the second 33n would be the 18. Is this correct. The stars on the schematic represent the lowest for low end and highest on hi values?
Sorry if that sounds incoherent.