MODEL HISTORY:

The basic topology of this stereo amplifier dates back to old days back at the VTL factory. This model saw its earliest roots in the VTL Stereo 75 & 90 models. (If you have one of those, do not contact us about it. Please contact VTL if you have a VTL amplifier...)

In about 1992 a special gold-plated 10th Anniversary Triode 60 Stereo Integrated Amplifier was made. A few of these were branded MANLEY. We have not seen any of these since then, except for this blurry picture of one from Hong Kong: As you can see, this model used larger octal tubes for input and driver tubes, 6SL7 and 6SN7's, respectively.

The push-pull KT90-based output stage was built hard strapped to Triode and produced around 60 watts. Output transformers were the Mercury Magnetics VTO-100, and the power tranny was also built by Mercury. The transformer covers were gold plated as was the milled brass top deck of the amplifier. The chassis side members, front panel, and rear panel were machined billet aluminum anodised black.

On the engraved front panel were two volume controls, one per channel, which allowed the amplifier to be used as a stereo integrated unit. The rear pair of RCA jacks fed these volume controls while the front panel pair of RCAs went directly into the input tube grids enabling the amp to be used as a normal stereo amplifier presuming you had means of controlling your volume levels elsewhere (using a preamp for instance).

There were no owner's manuals for these. Just the basic info in the VTL Book was good enough to go off of back then.

Also from 1992 was this one-off prototype that evolved from the VTL Stereo 90/90 and the 10th Anniversary Triode 60, and was built just prior to the split between Manley and VTL. This version used 4 x 12AT7 for all of the input and driver tubes, and the output tubes were KT90's from the Ei factory in Yugoslavia. David Manley had a wooden chassis made of beautiful Paduk that held a machined aluminum flat deck plate. This construction evolved into the later "Euro Series" aka "Open Series" GY Stereo GY 100 power amplifier.

Thank you to Luis for sending us these pictures of his rare Manley stereo power amplifier, still going strong almost 20 years later with no problems!

At Manley Labs:

After the Manley-VTL breakup in 1993, the first Manley stereo amplifier produced at the new Manley Labs factory was the Manley 'Euro' Stereo 100 using the funky russian GY50 output tubes. The GY50 Stereo 100 amplifiers were built from 10/1993 until about 9/1995. There were about 34 of these built carrying serial numbers MANES100001 - 034. 

The GY50 output tubes use a 12V heater and were originally used in Soviet tanks, (so the story goes). They are super-rugged tubes and have a whole cage structure that holds them sturdily in their ceramic sockets. We have tons of these in stock, by the way, as we are no longer producing any amps with these tubes...

Basic topology/circuitry of these GY50 Stereo 100 amps was "the same ol' same ol". No surprises here. Input and driver tubes were all 12AT7/ECC81 Yugoslav Ei 9-pin tubes. The chassis was all 1/4" billet aluminum. It looked like this:

Manley GY50 Stereo 100 Amplifier: 

• Vacuum tubes:

• Output tubes: 4 x GY50

• Driver tubes: 2 x 6414 (early units might have used 6350 so be sure to check!)

• Input tubes: 2 x 12AT7/ECC81

• Max. power @ 1.5% THD: 95 watts

• Input sensitivity: 800mV

• Input Impedance: 100 kOhms

• Output load impedance: 5 Ohm

• Freq. Response +-0.5 dB: 10 Hz- 35 kHz

• S/N ratio: 80dB

• Power consumption: 170W quiescent, 220W at full power

• Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.

• Operating Mains Voltage changeable with power transformer re-wiring and fuse value change.

• Mains Fuse 100 to 120V operation: 6A SLO-BLO MDA or MDL 1/4” x 1 1/4”

• Mains Fuse 220 to 240V operation: 3A SLO-BLO MDA or MDL 1/4” x 1 1/4”

• B+ Fuses: 1A SLO-BLO MDA or MDL 1/4” x 1 1/4” one per channel to protect output transformers

• Mains Voltage Frequency: 50~60 Hz

• Badge Illumination: Incandescent lamp “FUSE LAMP STYLE” 8V 0.15mA. Dimensions are 1/4" x 1 1/4"

• Dimensions: W=19", L=14.5", H=7.5"

• Shipping weight: 46 Ibs.

EveAnna: "I still use one of these GY50 amps at home to drive a pair of little ProAc Super Tablettes on my home-office desktop, and I have had this same set-up since the mid 1990’s with no problems. I never even bother to check the bias. The dang thing just keeps on workin' even though one of the output tube's plates do glow quite red! I replaced the illuminated MANLEY badge with a piece of metal holding two volume controls which are fed by my computer's sound card. So I use mine as a one-input integrated amp. This, one could say, is the predecessor to the next model, the Direct Input Stereo 100/100..."

The next model change to the Direct Input Stereo 100 version coincided with our factory-wide cosmetic switch to gaudy 24K gold in early 1996 right before David Manley left the company and moved to France.

By 2001 EveAnna switched us back to good ol' "Manley Blue" and renamed this model Manley 100/100 Stereo Integrated.

Serial Numbers:

MDS1035 - 045 (except for 043) were gold. 
MDS1046 - 052 (and 043) were Manley Blue and then we killed off this model for good after the last one shipped out in Nov. 2003.

The Manley 100 /100 Integrated Amplifier was our biggest stereo or two-channel model on a single chassis employing a common power transformer but with dual-channel rectification and separate filter / reservoir capacity banks. Retail price was $4400 USD.

Three inputs were provided (TAPE. CD, & TUNER) together with a precision stepped volume-control ensuring absolute channel balance, or sometimes a well-matched Noble® stereo potentiometer. There was a fourth position on the input select switch marked "DIRECT" which bypassed the input switching and volume-control enabling this unit to be used like a normal stereo amp with a separate preamplifier.

A mute switch was also provided, very handy for avoiding noise when swapping interconnect cables or front end electronics so you didn't have to alter your volume control setting. The chassis parts grew thicker and sturdier after seeing previous incarnations suffer shipping damage occasionally.

In each output stage was a pair of the luscious Teslovak KT88S (pictured above) or the well-proven Russian 6550C's running in ULTRA-LINEAR (or PARTlAL-TRIODE) mode.