PDA

View Full Version : Preamp Bakeoff



Bigman80
28-08-2018, 16:43
After hearing stories of the prowess of a little known Chinese preamp from Alan, we decided to get together and put the preamps we have through a little bakeoff to see how the Chinese (RVC) job fared.

Here is the ebay listing. I have not taken a picture of Alan's so this will have to do. The new RVC has had a SS buffer added to give it an active output too.

https://www.ebay.co.uk/itm/Volume-Remote-Control-Relay-128-Steps-Exponential-Constant-input-impedance-4-CH/142811721459?hash=item21403deef3:g:EZQAAOSw6CJbCmL 8

The first preamp in the system was the KIN to get a measure of where we were starting from. We used the Half Speed remaster of "Queen - Greatest Hits"

We gave the RVC a thorough working over. In passive mode i wasn't impressed, it was a little flabby in the bass and just didn't have any urgency. Guitar riffs were a bit lazy and lacked a little of the crunch i look for when Brian May plays certain riffs. The soundstage was ok width wise and the HF were very smooth as was the whole frequency range. The resolution however, was better.

In the new active mode, I must say i felt it was cleaner and more defined. More so than the KIN but the soundstage seemed a little more central. There was also a little less depth, but on the whole i will say that there is a massive amount of quality here for £100 (£150 modded i think). Riffs and drums had urgency and the vocals from Mercury were clean and expressive. I did also feel that whilst it was excellent, i did get a bit of fatigue from the HF, which in truth got a bit hard at times. cymbals felt a bit glaring at times too, which is certainly not something i had heard in Alans system before. I suspect this is due to the Opamps providing the gain in the active section. I am pretty sure a DCB1 buffer board or something which offered unity gain would remove this issue. The sound became far more driven and the urgency was impressive.

In all truth, in standard form, i would suggest there is very little or anything for £100 that would better it. With a few choice mods and an active stage fitted, it became a genuine contender for most preamps. Seriously good but the biggest issue is the HF hardness which caused some fatigue but that could be down to the opamps and i would really like to hear it with a good buffer board of some type.

We decided to put my DCB1 with Khozmo SA in and see what happened next.

We switched to a track from a Bluenote album.

Instantly, the difference was clear. The Saxophonist jumped from the speakers and was in the room with us. I am not kidding either. Alan's face was a picture!!

The DCB1 was flawless to my ears, there is a very organic way to which things are allowed to pass through it. The Saxophonist runs out of breath and you are willing him to breathe. The difference between the KIN and the RVC was in the ultimate transparency and the way in which it has little impact on the sound. It has depth, width, scale, bass slams and you get EXACTLY out of the pre as to what goes in IMO. We went back and used the same track on the RVC and the saxophonist got back into the speaker and it lost some depth, the soundstage became flatter. It lost the lucidity and 3D quality the DCB1 allowed to be displayed.

We put the KIN back in with the same track and it got a bit more organic but the sound wasn't as clean as with the RVC or the DCB1.

Out of the 3, IMO the DCB1 with Khozmo was way ahead.

We got the DCB1 on the scope and it makes no difference what volume it plays at, there is NO distortion at all.

In my humble opinion, the DCB1 with Khozmo is a preamp that belongs in the upper echelon of preamps. I have no idea how to beat it other than having no preamp at all.

There is a DCB1 on Pink fish media for sale for £350, it doesn't have a Khozmo but it does have a nice looking Stepped Attenuator. If i needed a preamp i would snap it up.

Is the RVC a giant killer? Well, it is certainly very impressive and for the price its remarkable. I liken it to the presentation of the Slagle AVC i had. I'd be hard pressed to pick a winner between the two. It is definitely something that should be heard if you need a preamp on a budget. What could be better? Not much that i can think of.

Thanks to Alan for a really enjoyable morning as usual!

Firebottle
28-08-2018, 17:53
Yes it was an excellent morning. Another very good session to drill down into the important traits that give world class sound.

Oli's assessments above are spot on. We are listening in the upper echelons of performance so differences are small and need correspondingly good support equipment. The 57's having virtually no colouration are a brilliant window into the soundstage. The dual mono Firebottle power amp just seems to pass what ever you throw at it, fortunately.

The Khozmo attenuator/DCB1 Pass buffer board preamp that Oli has built is the most transparent preamp I have heard. As stated the saxophonist was in the room, this is the benchmark that all preamps should aspire to.

The Chinese RVC is a stone cold bargain for what it offers, but I am on the quest to lift the performance with some judicious mods to cable and some of the resistors. The quality of the following buffer stage is also under scrutiny, so more developments await.

STD305M
28-08-2018, 18:33
Hi Alan, Oliver,

I guess I'm in for a real treat when i pick up my mono's from Alan and get the DCB1 turbo finished.

Id Like to thank both of you, Alan for building me my new mono's and finishing my dcb1 build and Oliver for starting me down the road to ruin, will i ever be satisfied???
I guess ill have to wait and see.

Steve...

Bigman80
28-08-2018, 19:17
Yes it was an excellent morning. Another very good session to drill down into the important traits that give world class sound.

Oli's assessments above are spot on. We are listening in the upper echelons of performance so differences are small and need correspondingly good support equipment. The 57's having virtually no colouration are a brilliant window into the soundstage. The dual mono Firebottle power amp just seems to pass what ever you throw at it, fortunately.

The Khozmo attenuator/DCB1 Pass buffer board preamp that Oli has built is the most transparent preamp I have heard. As stated the saxophonist was in the room, this is the benchmark that all preamps should aspire to.

The Chinese RVC is a stone cold bargain for what it offers, but I am on the quest to lift the performance with some judicious mods to cable and some of the resistors. The quality of the following buffer stage is also under scrutiny, so more developments await.Yes, I'd forgotten to mention the Firebottle DMPA. It was superb again and as you said, conveyed all it was given. I really like the way they deliver music.

Sent from my VKY-L09 using Tapatalk

Bigman80
28-08-2018, 19:18
Hi Alan, Oliver,

I guess I'm in for a real treat when i pick up my mono's from Alan and get the DCB1 turbo finished.

Id Like to thank both of you, Alan for building me my new mono's and finishing my dcb1 build and Oliver for starting me down the road to ruin, will i ever be satisfied???
I guess ill have to wait and see.

Steve...You're going to have to let the Khozmo bed in but once everything has.......wow.

It's just a superb preamp and wants for nothing.

Sent from my VKY-L09 using Tapatalk

smangus
28-08-2018, 19:23
Hi Alan, Oliver,

I guess I'm in for a real treat when i pick up my mono's from Alan and get the DCB1 turbo finished.

Id Like to thank both of you, Alan for building me my new mono's and finishing my dcb1 build and Oliver for starting me down the road to ruin, will i ever be satisfied???
I guess ill have to wait and see.

Steve...

I'm part way down the "Olibottle"TM path myself with the otp and monos . You could do a lot worse ! :) I am really enjoying them and they are gents to deal with also.. You'll love the monos.

Bigman80
28-08-2018, 20:16
I'm part way down the "Olibottle"TM path myself with the otp and monos . You could do a lot worse ! :) I am really enjoying them and they are gents to deal with also.. You'll love the monos."Olibottle" [emoji23][emoji23]

I'm glad you're enjoying them mate. They are very very good. Go get yourself that DCB1 off PFM and see how good they really are.



Sent from my VKY-L09 using Tapatalk

smangus
28-08-2018, 20:46
cheers need my pennies for my highland whisky trip next week :eyebrows:

Not going to start mucking about with preamps just yet. upgrade path will be otp2 then tonearm 1st! The Linn Classik is working just fine as a pre at the moment. :)

Bigman80
28-08-2018, 20:52
cheers need my pennies for my highland whisky trip next week :eyebrows:

Not going to start mucking about with preamps just yet. upgrade path will be otp2 then tonearm 1st! The Linn Classik is working just fine as a pre at the moment. :)Oh, I like a nice whiskey. Money well spent mate.

Fair enough, the upgrade path can wait!!

Sent from my VKY-L09 using Tapatalk

STD305M
28-08-2018, 21:24
Oh, I like a nice whiskey. Money well spent mate.

Fair enough, the upgrade path can wait!!

Sent from my VKY-L09 using Tapatalk

Id better bring up a bottle of 25 year old malt i opened but didn't like
All yours mate

Bigman80
28-08-2018, 21:38
Id better bring up a bottle of 25 year old malt i opened but didn't like
All yours mate🤤 I'll look forward to that. Top man, cheers Steve [emoji3]

Sent from my VKY-L09 using Tapatalk

hifinutt
29-08-2018, 12:49
thanks for this write up , just love trying pre amps and the dcb1 does sound worth a go . recently had the schiit saga valve passive pre in the system and it was stonking , if i still have it i would love to try it against some of those pre amps . i am now using the schiit freya with the firebottle monos in valve form and it has a big full bloodied , compelling sound . slightly more weighty than the saga . highly recommended at 725 new . i am very impressed with it and it really gels with the f/b monos

Bigman80
29-08-2018, 12:53
Hi Phil!

If you fancy it, give Alan a shout and compare against his RVC. He claims my suggestion of replacing the wiring with some of my cable innards has raised its game again and could possibly challenge the DCB1.

Hes also going to add some takman resistors which could help further.

I'd suggest you'd probably be impressed.

I am also happy to bring the DCB1 over if you fancy a listen. After what it did for Alan's system yesterday, I'd be stunned if you didn't want one.
thanks for this write up , just love trying pre amps and the dcb1 does sound worth a go . recently had the schiit saga valve passive pre in the system and it was stonking , if i still have it i would love to try it against some of those pre amps . i am now using the schiit freya with the firebottle monos in valve form and it has a big full bloodied , compelling sound . slightly more weighty than the saga . highly recommended at 725 new . i am very impressed with it and it really gels with the f/b monos

Sent from my VKY-L09 using Tapatalk

hifinutt
29-08-2018, 13:15
thanks ollie , would love to hear the dcb1 in my system , you would love the RFC taus , they are sensational ....well i think so anyway !!!

working 6-7 days a week at moment but when things ease off i will do that

Bigman80
29-08-2018, 14:40
thanks ollie , would love to hear the dcb1 in my system , you would love the RFC taus , they are sensational ....well i think so anyway !!!

working 6-7 days a week at moment but when things ease off i will do thatNo worries, we will sort something out

Sent from my VKY-L09 using Tapatalk

Firebottle
29-08-2018, 15:59
A valve output board came up at the right time in the classifieds (thanks JohnJo) so I have converted it into a valve buffer.

It is lashed into a temporary case and wired into the system from the passive outputs of the pre.

It sounds sensational, a touch more organic than the chip buffer. Need to get a nice case and box it properly.

http://i64.tinypic.com/kcjfus.jpg

JohnJo
29-08-2018, 16:51
A valve output board came up at the right time in the classifieds (thanks JohnJo) so I have converted it into a valve buffer.

It is lashed into a temporary case and wired into the system from the passive outputs of the pre.

It sounds sensational, a touch more organic than the chip buffer. Need to get a nice case and box it properly.

http://i64.tinypic.com/kcjfus.jpg

Great to see this getting used Alan :cool:

Nice fit on the output caps :)

Macca
29-08-2018, 16:57
No worries, we will sort something out

Sent from my VKY-L09 using Tapatalk

I would also like a go on the dcb1 at some point.

Bigman80
29-08-2018, 17:01
Looks like I'm going to be busy [emoji23]

No worries at all matey, I'll bring it up if want. We can discuss all those unused vinyls you have [emoji6]

I'll drop you a message with some dates ive got free. See if we can sort something out.

I would also like a go on the dcb1 at some point.

Sent from my VKY-L09 using Tapatalk

chiily
07-09-2018, 18:40
Here is the ebay listing. I have not taken a picture of Alan's so this will have to do. The new RVC has had a SS buffer added to give it an active output too.

https://www.ebay.co.uk/itm/Volume-Remote-Control-Relay-128-Steps-Exponential-Constant-input-impedance-4-CH/142811721459?hash=item21403deef3:g:EZQAAOSw6CJbCmL 8


Is that case earthed?

Bigman80
07-09-2018, 18:41
Not when you get it, it must be done on arrival.
Is that case earthed?

Sent from my VKY-L09 using Tapatalk

Bigman80
20-08-2019, 09:36
Old thread but related to the RVC from china.

ASR review:

https://www.audiosciencereview.com/forum/index.php?threads/review-measurements-of-talema-relay-pre-amp.8331/

Firebottle
20-08-2019, 09:44
Hmm, interesting. Never had any issues with noise with mine.

Bigman80
20-08-2019, 09:56
Hmm, interesting. Never had any issues with noise with mine.

They are pretty thorough over there at ASR.

Maybe quality control needs a smacked arse

Macca
20-08-2019, 11:08
The noise is very low, you'd be doing well to be able to hear its effect. Their only criticism seems to be that it is not perfect. But it's a hundred bucks from China so not really a big deal.

Firebottle
20-08-2019, 12:13
Agreed, why so many mains harmonics I don't know.
The psu arrangement is very traditional, transformer, bridge rectifier, smoothing cap then into two chip regulators.:scratch:

Pepperamip
21-08-2019, 05:21
I'm selling my one on ebay as we speak. I found it erring on the bright side in end so off she goes.

Sent from my CLT-L09 using Tapatalk

Bigman80
21-08-2019, 06:14
I'm selling my one on ebay as we speak. I found it erring on the bright side in end so off she goes.

Sent from my CLT-L09 using TapatalkYup, I understand your POV on it. That's where I ended up after a few days of listening.

Pepperamip
21-08-2019, 06:37
I must try a dcb1 build Ollie but I think I've let my passive khozmo put me off a bit.

Need to try one in my system somehow before I start shelling out on bits.

Sent from my CLT-L09 using Tapatalk

Bigman80
21-08-2019, 06:52
I must try a dcb1 build Ollie but I think I've let my passive khozmo put me off a bit.

Need to try one in my system somehow before I start shelling out on bits.

Sent from my CLT-L09 using TapatalkIf you were a bit closer I'd have brought it round for you to try [emoji17]

Not sure there is anyone local to you with one but they can be built cheaper than I built mine for. I just went all out lol