Intact Audio

Thanks, Daniel.

I will be getting 7.30k LCR inductors from Dave. My original thought was to use 4 x 0.1uF Teflon caps and pot them in something like bees wax. The 0.01uF could be either Mica or Teflon. However, I am not sure if I want to have both caps of the same type. Lately I am also thinking about ordering 0.4u...

Hey Dave,

Did you ever make some OPTs to drive headphones? The problem I see is the range of the headphone impedances: 32 - 600 Ohms.

Tony

I have it from pre-internet days when Arthur mailed it to me in an envelope.

Thanks, Naz.

TonyB

I do not see any reply, Naz.

TonyB

Naz wrote:

TonyB wrote:Hi Naz,

You mentioned a more complicated regulated power supply for your
Ref phono a while ago. Would you mind sharing its schematic?

I use RC tubed phono and am on 4th or 5th power supply. I always
want to try more.

Tony

Hi Naz,

You mentioned a more complicated regulated power supply for your
Ref phono a while ago. Would you mind sharing its schematic?

I use RC tubed phono and am on 4th or 5th power supply. I always
want to try more.

Tony

Now, it it only told me what is the optimum loading on the primary and secondary :D I am playing with Allnic Verito cartridge right now. It has 25 Ohm impedance and the recommended reflected load with SUT is 20 - 50 Ohms. (I tried 120 Ohms and the sound was too bright). My gut feeling is that the ca...

One set is made by certain Dave Slagle, the second Peerless 4665 and the third is one-off autotransformers ( 20dB gain, permalloy lams).

Regards,

TonyB

Now, it it only told me what is the optimum loading on the primary and secondary :D I am playing with Allnic Verito cartridge right now. It has 25 Ohm impedance and the recommended reflected load with SUT is 20 - 50 Ohms. (I tried 120 Ohms and the sound was too bright). My gut feeling is that the ca...

Hey Dave,

Is there an error in B17? Should not the last entry in the formula be B16?
(There is B15 there.)

Regards,

TonyB

Hi Lars,

Any news on the iRIAA? I would LOVE to see the Neumann circuit.

Regards,

TonyB

Hi Lars,

I did the same years ago with a solid state chip power amp. You should be looking at ferrite transformers, similar to what is used in switch mode power supplies.

TonyB

I am thinking about something I never thought I would: A phase splitter. It would be used in a FM radio stereo decoder. If my conceptual idea works, I would need two identical phase split signals from a single signal. Ruler flat amplitude and 0 degree phase 30Hz to 15kHz, 0dB gain, reasonably low ou...

Yes, the basic question is how was the inverse RIAA equalization done when the record was cut. I have "heard" that the Tango LCR RIAA is the inverse of the network used to cut records. That implied that LCR network was used to cut records. I would love to see the actual inverse cutting net...

After a number of years I again started playing with Dave's autoformers. Years ago I had them butt stacked. The ownside was a need for a large coupling capacitor before the autoformer: in order of 50uF. Now I soldered them properly in a Shallco switch and tried the recommended 6 x 6 stacking with on...

Excellent write up, Dave! That could explain why I never got my Jensen JT-346 MC step up to sound how I would like. The manufacturer recommends a secondary load of 6k81 Ohm in parallel with 4k12 Ohm + 680pF. I always thought that 6k81 Ohms is a too heavy load and I did not want to put an RC circuit ...

Hi Dave,

I have heard from people who built the LCR phono this way that for whatever reasons this low frequency impedance change does not seem to cause any significant deviations.

TonyB

Hi Dave, was having an email conversation with a friend and this all stems from the very educational thread started by Lars (revintage) on making a 600R LCR appear to the source as 1200 ohms. The most important thing i took from that thread was that the LCR's provide their impedance to the source in...

Yes, as with most things, it matters most how you make it.

TonyB

This approach almost begs to be tried with 1 - 3 Ohm low impedance cartidges - something like Audio Note MC cartridge where 5 Ohm load with 1:100 MC step up is recommended. On the other had, 120Ohms for Shelter 901 would be much harder to do.

TonyB

Thanks, Dave.

I sent you an email on Wednesday.

Regards,

TonyB

Hey Dave, I finally read the whole thread. I recently had ALLNIC 1500 II SE 600Ohm LCR phono on loan. I liked what I heard and as a result I started dusting off my old LCR files. I have Tango EQ-2L inductors which were used in this thread. But before I start playing with them, I want to check the hi...

Hi Nick, [quote="TonyB Properly done SUT peaking could take care of most of the sinx/x correction and some of the roll-off above 20kHz. I must admit to not fully understanding what you are saying there Nick. I forgot to include words "NON-OS DAC". Non-oversamplig DAC has an amplitude ...

... that I am tempted to try another DAC. Anybody has a spare CPLD?

Properly done SUT peaking could take care of most of the sinx/x correction and some of the roll-off above 20kHz.

Regards,

TonyB

PS: Do not forget to re-clock signals after the CPLD.

Hi Dave, I had a look at the amplifier. The driver used to run at 25mA and now it runs at 20mA DC. The worst case would be with a 20kOhm output tube grid resistor. In this case the output stage draws about 5mA from the driver. This is likely also the current drawn in A2 operation. My reasoning is th...

Hi Guys,

What were the impressions about the LR RIAA preamp at RMAF?

TonyB

Hi Dave,

I could be also game for a permalloy 1:1 IT that can handle 35mA. This way I could use either 45 or triode connected 46 as a driver.

Regards,

TonyB

Hi Dave, Sure, I can post the current sources. I have spoken with our electronics PhD and implemented his suggestions. I will scan it and either post it (if I figure how) or email it to you. Do you want to trade a working current source for 3 permalloy inductors for LCLCL filament power supply? I am...

Hi guys, So where did you get with the filament current cancellation scheme? I drew a couple of current sources capable of driving 2.5A and 18mH. My only concern is that any signal I insert with a current source will be amplified 40x. Three permalloy chokes for the LCLCL filament power supply would ...