Steve Luck - more inputs and balanced outputs is absolutely something you can do... this is DIY!!You’ll need a bigger chassis to have room for the additional input jacks, and either a doubling up of the PCB to run balanced at the circuit level, or a pair of SE to BAL output transformers.
Sounds like a great project! 😀
I have a second amp camp on order to make a pair and I'm interested in using the XLR inputs built into these for the reduction in distortion and increase in power mentioned in documentation. It also gives me something easier to sell on at some point to some one with less efficient speakers than I have.
I see that you can wire RCA to XLR plugs but I presume that would defeat some of the purpose/benefit.
I was hoping the new full pre-amp kit when it goes on sale would be set up to match the Amp camp amps. Extra inputs and switching I can manage but can you point me in the direction of some reading on how I could convert RCA output to XLR using transformers or how you'd make use of two PCB to do this as you mentioned. I need a diagram or two to understand how you'd do this.
Cheers
Steve
Steve Luck - post #4834
Pictures of your diy Pass amplifier
SE to BAL transformer - ART DTI 2-channel Hum Eliminator | Sweetwater
Which is basically this on the inside -
Pictures of your diy Pass amplifier
SE to BAL transformer - ART DTI 2-channel Hum Eliminator | Sweetwater
Which is basically this on the inside -
Steve, besides what 6L6 has posted the Jensen JT11P1 works very well. You may read the Application notes on the Jensen site as to how to wire them up.
nash
I have used the Jensen JT-11-P1 and it is an excellent transformer. While you are at it, reverse the primary winding connection and that will mean the output of the B1K will be in proper signal polarity so you will not need to reverse the loudspeaker leads. Also, pay attention to the data sheet and add the recommended damping network if your input pot is more than 10K ohms.
The bias voltage to the cathode heaters at T5 and T6 should be 0.6 VDC. I am measuring 0.667 VDC and 0.680 VDC respectively.
Is this still within acceptable limits?
Is this still within acceptable limits?
I have the B1K feeding my just completed F5 with results beyond expectations. Question is, I think both the B1K and F5 circuit designs invert the signal output. If I have those facts straight, does that mean the combination puts out a correct, non-inverted signal to the speakers so it isn't required to reverse the speaker polarity to get the phasing correct?
Maybe.
However, all that matters is what YOU decide sounds best of the two choices -
Speaker wires connected normally
Speaker wires connected “backwards”
Try both, flip them around a time or two. You’ll probably prefer one way to the other.
Whichever way you like is the way you should listen. Neither way is wrong.
However, all that matters is what YOU decide sounds best of the two choices -
Speaker wires connected normally
Speaker wires connected “backwards”
Try both, flip them around a time or two. You’ll probably prefer one way to the other.
Whichever way you like is the way you should listen. Neither way is wrong.
I don't think the phase thing will be real important until I utilize my subwoofer system with it. At that point I want it all in-phase. I'm hoping Nelson's new-fangled crossover will show some life soon. Or I may just invest in a miniDSP if that takes too long. I just really don't want anything digital in this chain.
I was wondering if the Korg would make a suitable output stage for a Twisted Pear BIII DAC, would anyone know?
This one? The Buffalo-IIIse Pro (Stereo Edition) 2-Channel DAC
I am NOT an authority, but I would think anything with a single ended output would work.
Also, I'm just getting into this DIY insanity. I am actually looking for a DAC kit for my DIY system. I'm looking very hard at the twisted pear site. Are you happy with that DAC? I also see there is an attenuator product there that looks interesting. Any experience with that? Joshua Tree - A Twisted Log Attenuator Could be a nice upgrade for my B1K.
I am NOT an authority, but I would think anything with a single ended output would work.
Also, I'm just getting into this DIY insanity. I am actually looking for a DAC kit for my DIY system. I'm looking very hard at the twisted pear site. Are you happy with that DAC? I also see there is an attenuator product there that looks interesting. Any experience with that? Joshua Tree - A Twisted Log Attenuator Could be a nice upgrade for my B1K.
Does that mean the Korg its not suitable for the TP DAC ?
TP have never recommended valve/tube output stages but I was never completely convinced that was a 100% unbiased view, mainly because it built one and it sounded good.
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I haven't used the Joshua Tree.
The IVY III I/V in SE form doesn't give the output levels I was expecting and was lead to beleive it would.
It has been ok for me althought I really have nothing to compare it to.
Input line transformer question
If a line input transformer is used for attenuation and phase correction (and side-benefit of galvanic isolation), could it replace the first buffer stage? The Jensen JT-10KB-DPC datasheet shows a output impedance of 225Ω. This seems to be similar to the output impedance of the first buffer stage that I observed in my LTSpice model of the B1K (assuming I'm reading it correctly).
A step-down transformer is specified because I simply don't need that much gain. And the pot ahead of it would be to further "tune" the overall gain structure of the system. Volume control would be in the digital domain (via Apple AirPlay).
I attached a schematic of what I was thinking of. The input buffer is replaced with the Jensen transformer and the first two coupling caps are eliminated. The output stage after the Nutube is unchanged.
If a line input transformer is used for attenuation and phase correction (and side-benefit of galvanic isolation), could it replace the first buffer stage? The Jensen JT-10KB-DPC datasheet shows a output impedance of 225Ω. This seems to be similar to the output impedance of the first buffer stage that I observed in my LTSpice model of the B1K (assuming I'm reading it correctly).
A step-down transformer is specified because I simply don't need that much gain. And the pot ahead of it would be to further "tune" the overall gain structure of the system. Volume control would be in the digital domain (via Apple AirPlay).
I attached a schematic of what I was thinking of. The input buffer is replaced with the Jensen transformer and the first two coupling caps are eliminated. The output stage after the Nutube is unchanged.
Attachments
signal xformers do not like DC across winding
you can use winding to route DC through it , but you can't place DC across it ( meaning - ends on different potentials)
you can use winding to route DC through it , but you can't place DC across it ( meaning - ends on different potentials)