FAQ  •  Register   •  Gallery •  Login

It is currently Tue Sep 23, 2014 5:27 pm

New Preamp

<<

hewlew1

"You Fuckin' Fucks"

Posts: 1248

Joined: Tue Feb 17, 2004 11:02 pm

Location: Northeast, Pa

Post Tue Feb 07, 2012 3:11 pm

New Preamp

I picked up a Mapletree Audio Designs Octal 6 Vacuum Tube Preamp to use with my Carverfest Monoblocks. It is here in Wilkes-Barre with me .Cant wait to try it out when I get home on Thursday. Picture is of the unit which is as depicted on Mapletree's site.
O6-4inputs.jpg
O6-4inputs.jpg (104.47 KiB) Viewed 632 times
"Carver Audio, why settle for less, just ask my neighbors"
C1,C2,CT3,CT6,CT7/3,CT23,CT26,C4000,The Receiver,M500,M500T/6,M1.5T,TFM24/2,TFM/25/2,TFM35,TFM35X,TFM/42,DTL200,TDR1700,DPL20,TX11,5.2Center,5.1Sub/3,Original Amazings,Platinum Amazings/2,AL3'S,Polk SDA SRS, Polk SDA 1C's, Polk RTA11's, Polk Monitor 10's,Monitor 7's, Sunfire 300x2 /5, Sunfire pre, Sunfire MK2 Sub, 4 Carverfest monoblocks, Mapletree Audio Designs Tube Preamp,Phase Linear Andromeda III speakers, Phase Linear 4000 Preamp, Dahlquist DQ-10's
CERTIFIED AMPLE PLIERS EXPERT
Some of the best fuckings we get during our lifetime will come from a relative!
I don't kiss ass and I dont take peoples shit, so dont expect it from me!
<<

elgrau

SILVER-7 TUBE AMP

Posts: 2892

Joined: Wed May 31, 2006 9:33 pm

Post Tue Feb 07, 2012 3:15 pm

Re: New Preamp

No remote?? :lol: :lol:
Family room: 400 disk changer with PS Audio Digital Link III DAC; Technics SL-1100A TT. QED Quenx1 IC's from DAC & TT to Adcom GTP-602 preamp/Tuner. AudioQuest King Cobra IC's from preamp to M1.0t mk-II opt2. QED Silver Spirals 4M wires to EPI 1000’s.
Living room: AudioQuest Black Mamba 8M IC's from family room preamp to Barcus-Berry 2002R Sonic Maximizer to GlowPower Zyxt IC's to Sunfire 300x2 to Nordost 6M bi-source wires to AOS 28" MDF spherical speakers using six 8" woofers and eight 1" dome tweeters symm. arranged around the surface.
SS system: CX-995V DVD to AV-705x 5 channel amp (center/rears) & M1.0t mk-II opt2(fronts).
Garage: TLM-3600 CDP to MXR150 Receiver (pre) to TFM-42 to EPI 400 speakers.
<<

Snoop65

User avatar

(pair of) SILVER-7t's

Posts: 2029

Joined: Mon Jun 28, 2010 9:04 pm

Location: A galaxy far far away

Post Tue Feb 07, 2012 3:15 pm

Re: New Preamp

Nice!!!! Have fun!!!! =D> =D> =D> =D> \:D/ \:D/ \:D/ \:D/
CARVER LIGHTSTAR REFERENCE+SUNFIRE CLASSIC TUBE PREAMPLIFIER+JBL XPL200+MUSIC HALL MMF-9.1+GRADO REFERENCE MASTER 1+CARVER SD/A 390t=WOW!!!!!!
<<

jjptkd

User avatar

SILVER-7 TUBE AMP

Posts: 2892

Joined: Wed Sep 22, 2010 4:50 pm

Location: Snohomish, WA

Post Tue Feb 07, 2012 3:31 pm

Re: New Preamp

Very nice!! =D> =D>
Sunfire TGP-III
Sunfire 405x5
PS Audio DL-III DAC
(2 Pairs) Klipsch Chorus II's
Klipsch RSW 15
<<

mbskeam

User avatar

SILVER-7t

Posts: 1982

Joined: Mon Jan 25, 2010 2:32 am

Location: Woodinville Wa

Post Tue Feb 07, 2012 3:37 pm

Re: New Preamp

what are the tubes?
I may have some .....
Mbskeam


#1 BLACK BEAUTY's made by the man, the myth, the legend Bob Carver
CARVER: TFM-75, TFM-45(3), SD/A-490T
SUNFIRE: Tube pre
2 sets of ALS'3, set of SILVERS, set of PLATS
AUDIOCONTROL: phase coupled activator
KENWOOD: BASIC M2a (2)

“Youth ages, immaturity is outgrown, ignorance can be educated, and drunkenness sobered, but stupid lasts forever.”
― Aristophanes

The only thing I'll feel......will be the RECOIL
Necronomicon Ex-Mortis....... Klaatu Barada Nikkto
"We should seek the greatest value of our action"
<<

engtaz

User avatar

"TAZ"

Posts: 5211

Joined: Sat Jun 30, 2007 1:43 pm

Location: Tampa, FL

Post Tue Feb 07, 2012 5:31 pm

Re: New Preamp

SCWEEEEEEEEEEEEEEET
engtaz


Carver M4.0T in front channels to Caver AL VI's in SACD & 2 Channel setup
C 16, PT 2400, Slim Device, Carver TX-8, 490T and Rega TT w Grado Gold cart in the 2 channel setup
Bogen SRB20 is computer amp
Carver PM-350 donated for youth church use
<<

Zoot Horn

User avatar

SILVER-7 TUBE AMP

Posts: 3129

Joined: Thu Nov 15, 2007 7:26 pm

Location: 4th Tower of Inverness

Post Tue Feb 07, 2012 6:38 pm

Re: New Preamp

Nice Harry,,I've heard alot of good things about Mapletree--enjoy.
<<

jerryj12

User avatar

TFM-6cb

Posts: 206

Joined: Sun Aug 24, 2008 12:30 am

Location: Atlanta, Area

Post Tue Feb 07, 2012 7:16 pm

Re: New Preamp

Found this online--- I would like to try one one day. Nice score!

First of all, I wish to thank Richard for the time and effort spent in building and reviewing the MAD Octal 6. Such reviews are a great service to the audiophile consumer. I am pleased that the Octal 6 provided a rewarding kit building experience. I certainly relied on my experiences years ago with Heath and Dynakits when designing the physical assembly procedures and instruction manual. Richard's listening impressions reflect the design intent to a large degree. The choice of carbon film resistors was taken to achieve a fuller, warmer sonic signature than is often obtained with (cheaper) generic metal film types. Both the review and customers' feedback seem to indicate that this objective has been met. It is also interesting that for Richard (and other listeners), the sonic differences in the two active topologies are in the first instance, subtle. Nevertheless, listeners soon develop a preference, which seems about equally split between the two. With the Octal 6, you do have a choice.

Perhaps a word about "tube rolling" would be helpful. The 12SX7GT is considered by many to be the top 12SN7GT type ever made and can be directly substituted. Also, there are metal versions of the 12J5GT and 6R7G which can be tried. Also, if at some point in the future the user wishes to use 6 V versions of the 12J5 and 12SN7, heater rewiring is quite straightforward. For now, the 12 V versions are a much better deal, as the price for NOS 6SN7GTs is out of sight.

Two modifications have been made to the Octal 6 since the review sample was shipped, which have significant impact on the performance. First, an Alps "Black Beauty" center-detent balance control is now included. This special control (which is no longer manufactured) provides zero attenuation at mid-position. This gives the Octal 6 about an 8 dB increase in gain in all modes, which is particularly welcome in the passive mode. The precision and reliability of the control are also welcome. Secondly, the position of the volume and balance controls in the circuit has been reversed to lower the output resistance of the passive path. This can have a significant impact on high frequency response when driving capacitive cable runs to the power amplifier. This is a seldom mentioned problem with passive control "preamplifiers".

Lastly, I am not happy with the fact that Richard heard low level hum when using the Octal 6. The samples I have built as assembled units certainly had no audible hum close to the speaker when used with a power amp with a gain of around 10 and speakers with 92 dB sensitivity. Higher gain power amps or more sensitive speakers will of course effectively amplify any output noise from any preamp to audible levels. With the dc heater supply and the use of shielded cable on all the inputs, every effort was taken to make the Octal 6 a very quiet preamp. If a customer is unsatisfied with any aspect of the Octal 6 kit performance (relative to the published specs), I am happy to have it shipped back for a tuneup at no cost to the customer except shipping.

Return to CARVERFEST 2011

Who is online

Users browsing this forum: No registered users and 1 guest

Powered by phpBB © 2011 phpBB Group.