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2 budget tube preamps - which one?


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I’m now running a very modest 2 channel system consisting of:

- Node2

- 2 x Pass ACA as mono blocks

- Adelaide Ascension Valve speakers

 

These are the two tube preamps I’ve found within my budget (remote is mandatory). Can anyone tell me what sort of difference I should expect between the two?

 

https://www.ebay.com.au/itm/353577253448?hash=item5252d8ba48:g:~vcAAOSwAdpg8YR0

 

https://www.ebay.com.au/itm/353570321284?hash=item52526ef384:g:kXEAAOSwFUVg6vHf

 

tubes4hifi.com sell the marantz version and seem to think it’s pretty good.

Edited by TheBlackDisc
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Weird, it opens for me….

 

6SN7 first-level amplified output, power transformer, a brand new transformer imported from the United States, CLC plus voltage regulator, working voltage 240V, imported original 27 type 100K potentiometer for volume control, tube socket EIZZ, CNC socket for RCA output, Teflon and wire U.S. West Electric cotton and hemp wire, filter U.S. West Electric 513 capacitor, output U.S. West Electric 439A capacitor, resistance British IRC, imported second-hand choke.


 

The rectifier tube can use 5V filament tubes, such as 5Z2P, 5Z4P, 5Z3P, 5AR4, etc. The gain of this machine is 12DB, the tube filament adopts DC power supply, the residual noise (volume potentiometer is turned to the maximum position) 0.2MV, imported silver solder soldering. Frequency response 10HZ-100KHZ=0DB. The characteristics of this first-level amplifier are transparent sound quality, quiet music background, high analytical power, and fairly balanced full-frequency performance, which makes the control of this machine very in place. The chassis aluminum alloy is 246MM long, 237MM wide and 50MM high.”

Hb48ca5a0f8f04c3fb94081d4c8806b4c2.jpg

 

Edited by MattyW
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Just now, Spider27 said:

 

How about Schiit Saga old model or newer model which is tube hyprid preamp with remote ?


I’d thought about it - and it’s probably my fallback - but have a hankering for that old-school valve sound.

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On 12/10/2021 at 9:32 AM, TheBlackDisc said:

I’m now running a very modest 2 channel system consisting of:

- Node2

- 2 x Pass ACA as mono blocks

- Adelaide Ascension Valve speakers

 

These are the two tube preamps I’ve found within my budget (remote is mandatory). Can anyone tell me what sort of difference I should expect between the two?

 

https://www.ebay.com.au/itm/353577253448?hash=item5252d8ba48:g:~vcAAOSwAdpg8YR0

 

https://www.ebay.com.au/itm/353570321284?hash=item52526ef384:g:kXEAAOSwFUVg6vHf

 

tubes4hifi.com sell the marantz version and seem to think it’s pretty good.

They appear to be the same unit, with different brand tubes. You can always tube roll.

I don't know the manufacturer, but it looks like it should be OK for a budget, especially with the number of inputs and remote.

Not sure what happens if there's a warranty issue.

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5 minutes ago, Gelert said:

They appear to be the same unit, with different brand tubes. You can always tube roll.

I don't know the manufacturer, but it looks like it should be OK for a budget, especially with the number of inputs and remote.

Not sure what happens if there's a warranty issue.


one has 3 tubes, and one 4 (supposedly based on the marantz 7 and some

kind of Conrad Johnson respectively).

Edited by TheBlackDisc
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14 minutes ago, TheBlackDisc said:


one has 3 tubes, and one 4 (supposedly based on the marantz 7 and some

kind of Conrad Johnson respectively).

Tempting. I'd have to speak with the wife, and I'm on thin ice even for a budget pre-amp.

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Asking @andyr as you seem to be the expert on all things impedance etc matching - do you know if these will suit the pass aca?

 

the bottom of the specs mention optional 50k or 100k resistance, but I seriously have NO IDEA what I’m looking at!

Edited by TheBlackDisc
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1 hour ago, TheBlackDisc said:

Asking @andyr as you seem to be the expert on all things impedance etc matching - do you know if these will suit the pass aca?

 

Mmmm, hopefully, I can help.  :)

 

I found this review about the Pass ACA:

Eric's Hi-Fi Blog: Pass Labs ACA Power Amplifier (singaporehifi.blogspot.com)

 

- which says its input impedance (Zin) is 10K ohms.  :(  :(

 

Conventional wisdom says that the output impedance (Zout) of a component needs to be at the very most 1/10th of the Zin of the component which follows it in the signal chain.  I personally like it to be no more than 1/50th.

 

Following the Zin/Zout rule, a preamp would need a Zout of 1K ohms at the most (preferably <200 ohms), to work well with the ACA.  This is easy to achieve with an ss preamp ... but not with a tube unit.

 

I looked at the 2 links you provided ... but couldn't find Zout mentioned.  However, tube amps generally have a Zout a lot greater than 1K - so, no, I don't think they are going to work with the ACA.

 

I suggest you should ask on the ACA thread on diyAudio, whether the Zin of the ACA can be increased from 10K to 47K without degrading the amp's sonics.  If this can be done ... then those tube preamps will probably work.

 

WRT:

 

1 hour ago, TheBlackDisc said:

the bottom of the specs mention optional 50k or 100k resistance

 

... I suspect they are talking about changing the Zin of the preamp from the default 47K ... to 50K or 100K.  Unfortunately, that won't help you as far as the ACA is concerned.  :(

 

Good luck!

Andy

 

Edited by andyr
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1 hour ago, Gelert said:

Tempting. I'd have to speak with the wife, and I'm on thin ice even for a budget pre-amp.

 

But I thought you have a Willsenton integrated - so why do you want a preamp?

Andy

 

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I think I found one - 600ohm output impedance:

 

https://www.china-hifi-audio.com/en/xiangsheng-valve-amplifier-dac-c-36/xiangsheng-728a-vacuum-tube-pre-amplifier-shigeru-wada-silver-p-364

 

2 hours ago, andyr said:

 

Mmmm, hopefully, I can help.  :)

 

I found this review about the Pass ACA:

Eric's Hi-Fi Blog: Pass Labs ACA Power Amplifier (singaporehifi.blogspot.com)

 

- which says its input impedance (Zin) is 10K ohms.  :(  :(

 

Conventional wisdom says that the output impedance (Zout) of a component needs to be at the very most 1/10th of the Zin of the component which follows it in the signal chain.  I personally like it to be no more than 1/50th.

 

Following the Zin/Zout rule, a preamp would need a Zout of 1K ohms at the most (preferably <200 ohms), to work well with the ACA.  This is easy to achieve with an ss preamp ... but not with a tube unit.

 

I looked at the 2 links you provided ... but couldn't find Zout mentioned.  However, tube amps generally have a Zout a lot greater than 1K - so, no, I don't think they are going to work with the ACA.

 

I suggest you should ask on the ACA thread on diyAudio, whether the Zin of the ACA can be increased from 10K to 47K without degrading the amp's sonics.  If this can be done ... then those tube preamps will probably work.

 

WRT:

 

 

... I suspect they are talking about changing the Zin of the preamp from the default 47K ... to 50K or 100K.  Unfortunately, that won't help you as far as the ACA is concerned.  :(

 

Good luck!

Andy

 

:

 

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2 minutes ago, andyr said:

 

Seems to be right - yes, 600 ohms should work fine into 10K Zin.

 

I suggest you order the 240v version.

 

Andy

 


Will do! Ty for your help, saved me a kerfuffle!

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2 minutes ago, TheBlackDisc said:


Will do! Ty for your help, saved me a kerfuffle!

 

 

:thumb:

 

Hope it goes well.

 

Incidentally, your ACA ia about 5w right?  (Forget whether this was into 8 ohms or 4 ohms.)

 

When lockdown rules allow it, you might care to hear one of my recently built 40w Class A amps (from diyAudio) - just to hear what more watts does for you.  🙂

 

Andy

 

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1 minute ago, andyr said:

 

:thumb:

 

Hope it goes well.

 

Incidentally, your ACA ia about 5w right?  (Forget whether this was into 8 ohms or 4 ohms.)

 

When lockdown rules allow it, you might care to hear one of my recently built 40w Class A amps (from diyAudio) - just to hear what more watts does for you.  🙂

 

Andy

 


mom running them as monos - so I get 15 watts @ 8ohms.

 

I’d love to, but I’ve moved to Canberra :/

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32 minutes ago, TheBlackDisc said:

I’d love to, but I’ve moved to Canberra :/

 

Aah - perhaps you should change your 'Location' then.  🙂

 

Andy

 

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16 hours ago, andyr said:

 

But I thought you have a Willsenton integrated - so why do you want a preamp?

Andy

 

Good question. The Willsenton has a pre-in option, although it technically doesn't run as a power amp through that input. The preamp tubes are still in the line, but the volume and switching modes have been bypassed. An external preamp does slightly improve the overall sound of the amp; but more importantly, it gives much better control of the volume via a remote. The Willsenton's remote jumps in big increments, so volume goes from soft to loud with one press of the button.  That can be annoying.

 

I prefer the sound and convenience of the Regum/Willsenton combination than using the Willsenton as an integrated. 

 

I've also replaced the tubes with NOS stock, played around with cables, and room placement of my floor standing speakers, and reckon that I've almost got the sound near to what I've been searching for.

 

Haven't tried streaming yet. That's another rabbit hole to go down.

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