Sub sonic filter

[jwrosenthal]

Hey guys,

Which models of naks had a sub-sonic filter? Both of my main turntables are Thorens 124's and although you can't detect the rumble through the speakers (except for a touch of sub flutter), it is audible through headphones on tape playback and is driving me crazy! My rumble is in the 20-30hz range and I was wondering if the sub-sonic filter on some of the naks would deal with this.
I have already tried the sub-filter sold by KAB and it worked a bit on my table, but not enough to justify keeping it (not to knock it, it worked very well on open reel playback on which I had some rumble).
James R.

[perry]

Welcome to TH. I also frequent "the other site" as perryinva. vintagedassette.com has every Nak listed with the specs. WAY too many with a subsonic filter to list. The Dragon and RX-505/303 all have them, as well as any of the later TOTLs, CR5A/7A, ZX-7/9, etc. It is a VERY good filter.

[Marek]

James

Welcome!*thumbsup*

Are you saying that rumble is not a problem when played back on your turntable, but only with recordings of your turntable?

Hey guys,

Which models of naks had a sub-sonic filter? Both of my main turntables are Thorens 124's and although you can't detect the rumble through the speakers (except for a touch of sub flutter), it is audible through headphones on tape playback and is driving me crazy! My rumble is in the 20-30hz range and I was wondering if the sub-sonic filter on some of the naks would deal with this.
I have already tried the sub-filter sold by KAB and it worked a bit on my table, but not enough to justify keeping it (not to knock it, it worked very well on open reel playback on which I had some rumble).
James R.

[jwrosenthal]

James

Welcome!*thumbsup*

Are you saying that rumble is not a problem when played back on your turntable, but only with recordings of your turntable?

No, the rumble is always there with the Thorens. I have two of them, one in factory configuration and one tweaked to hell for deadening and rumble control which is much quieter than the stock (gummi motor mounts, silicon nitrate ball-on-ball spindle, MDF plinth, rebuilt idler, the works).
Part of the joy of these vintage idler tables is the pacing, rhythmic drive and power they put into the music....but like anything wonderful, there is always a down-side, which in the case of idler tables is rumble.
The problem lies in the fact that a quality tape-deck, with quality tape will accurately reproduce EXACTLY what is being recorded...warts and all.

On playback in my home system with speakers, the rumble is almost inaudible (unless you put your head against the speakers during a silent passage or put your hand on the LF driver), but I got back into cassette with the sole purpose of bringing my vinyl on the road with me (although I have been listening to this Nak at home quiet a bit), via cassette, and you can hear everything through my headphones. CD's recorded with my CR1A are dead quiet and blissfully dynamic on my Walkman through my AKG cans, but when listening to recordings made from vinyl, it sounds like a truck is pulling up the street.

I could just make my recordings using my Technics SL1200mkII (my work turntable which is dead quiet) which has an identical Denon DL103 as my main Thorens, but doesn't have the same flavor as the Thorens/SME as it lacks the liveliness of that combo, hence if I could cut the LF below the rumble point (about 25hz) I would be in good shape.

James R.

[gamve]

Welcome to TH. I also frequent "the other site" as perryinva. vintagedassette.com has every Nak listed with the specs. WAY too many with a subsonic filter to list. The Dragon and RX-505/303 all have them, as well as any of the later TOTLs, CR5A/7A, ZX-7/9, etc. It is a VERY good filter.

Perry, the CR7A has the subsonic filter but not the ZX9/7 models

[perry]

Thanks for the correction, gam, I was making an assumption on them, as I thought they were RX-505/Dragon TOTL contemporaries.That is surprising, especially as they were generally considered top recording decks. The Revox B215 does not have one either, nor my Yamahas, including the K-1020 and K960. Interesting.

[gamve]

Thanks for the correction, gam, I was making an assumption on them, as I thought they were RX-505/Dragon TOTL contemporaries.That is surprising, especially as they were generally considered top recording decks. The Revox B215 does not have one either, nor my Yamahas, including the K-1020 and K960. Interesting.

I'm spoiled as my Sansui AU-X1 also has a subsonic filter. I will have to work out which one works best or if in fact the amplifier filter is in circuit when the tape loop is in operation.

[Marek]

I wonder how these would work to filter tt rumble.?

http://store.hlabs.com/pk4/store.pl?section=12

[perry]

One of the reasons I got my Mac C33 pre-amps was the ability to switch into or out of any of the filters or equalizer controls, as well as totally separate playback and record paths and circuits. FWIW, the Nak one appears to be lower and sharper than the low filter on my Mac.

[Marek]

Many macs have built in sub sonic and ultrasonic filtering.

C33's a very nice unit.*thumbsup*

One of the reasons I got my Mac C33 pre-amps was the ability to switch into or out of any of the filters or equalizer controls, as well as totally separate playback and record paths and circuits. FWIW, the Nak one appears to be lower and sharper than the low filter on my Mac.