The TL-6.5 Series II incorporates most of the advanced technology found in VTL’s flagship preamplifier, the TL-7.5 Series III, for a dramatically higher level of performance compared to the original design. The new version features an extensively revised power supply based on current-sourced shunt regulator technology that minimizes impact on the audio signal. Far more precise power regulation yields dramatically improved rejection of noise and AC fluctuation.
The completely redesigned high current gain stage utilizes newly available FET technology developed for green technologies such as solar panels and electric cars that require a normally-on state. Unlike MOSFETs that need to be biased on, normally-on devices operate more like vacuum tubes in the audio output stage, with simpler circuits that continuously conduct current, resulting in a more tube-like sound. The high-current gain stage is shock-mounted like the TL-7.5, and has been further optimized for linearity, with zero global negative feedback.
Also included in the upgrade are re-voiced audiophile grade capacitors and additional bypassing.
Enhancements to the Series II result in an overall more tube-like sonic character, with more defined images in the listening space, a higher level of inner detail, and a dramatically improved mid-bass and midrange. The TL6.5 Series II is an exceptional match with any of VTL’s other Signature products.
Functionality features
Audio circuit features
- Fully balanced differential circuit with balanced in and out, and mirror-image layout
- Simple 2-stage circuit topology with differential gain stage and output buffers for musical purity and integrity
- Ultra low impedance output stage to drive any length of cable and any power amplifier/paralleled amplifier/subwoofer load
- 20 microfarad output capacitors for powerful bass control
- Tube complement: 2 x 12AU7/ECC82 tubes
- Gain switching between normal gain and low gain with 6dB gain reduction
- Single fully balanced differential 95-step 70dB discrete resistor relay attenuator for all attenuation functions
Control and power supply features
- Precision regulation
- Ramped B+ filament soft-start power up for extended tube life
- Huge energy storage power supply for elimination of AC fluctuation and noise rejection
- Low noise processor control design for all functions
User interface features
- Processor loop – any of 8 inputs can be assigned as fixed unity gain pass through
- Tape monitor function for both tape loops
- 2 separately programmable trigger outputs
- Bi-directional RS-232 interface
- Programmable input offsets
- Rigid Combination steel and non-magnetic chassis and machined aluminum remote wand
Additional features
- New FET device output stage for more tube-like sound and simpler bias circuit
- Improved current source for improved musicality and better single-ended operation
- Zero Global NFB for vastly improved faster dynamic and tonal resolution, and unconditionally stable circuit, without any phase shift.
- All audiophile grade capacitors in signal path with bypass system for improved HF resolution
- Vastly improved lower impact and greater precision-regulated current-sourced shunt power supply
- Teflon power supply bypass caps for improved top end
- Microphonically damped tube gain stage for greater vibration noise elimination
Documentation
TL6.5 Data Sheet
Technical Specifications
| Vacuum Tube Complement | 2 x 12AU7 | |||
| Inputs | 3 pairs balanced/XLR or RCA single-ended, 5 pairs single-ended/RCA | |||
| Outputs | 1 pair balanced out, 2 pairs single-ended RCA out, 2 pairs single-ended RCA buffered Tape Out | |||
| Remote control functions | Power, Source Select, Volume up/down, Mute, Fade, Balance Control, Phase Reverse | |||
| Gain | NORM: 14 dB single ended, 19.2 dB balanced LOW: 7 dB single ended, 13 dB balanced |
|||
| Output impedance | 50Ω (500Ω @ 20Hz) | |||
| Input impedance | Balanced: 112kΩ (36kΩ min) Single ended: 54kΩ (18kΩ min) |
|||
| Frequency Response +0, -o.3 dB | 10Hz – 200kHz, into 5kΩ 1000pF load | |||
| Maximum Output Voltage <1% THD | 13V 10Hz – 200kHz into >5kΩ load | |||
| Channel separation | >100dB @ 1kHz (>80dB @ 20kHz) | |||
| Power consumption | 150W | |||
| Dimensions W x D x H | 17.5 x 17.5 x 6 inches (44.5 x 44.5 x 15.3 cm) | |||
| Weight | 46lbs (20.86Kg) unpacked, 57lbs (25.85Kg) fully packed | |||
Hi-Fi+ Editor’s Choice 2020
VTL TL6.5 Series II Signature line stage and S-200 Signature power Amplifier
“It (TL6.5 II) has added serious low-frequency extension and grip to the mix, moving it far closer to the flagship 7.5 in overall performance.”
“The S-200’s neat trick is to deliver a realistic impression of weight and scale, pitch and extension.”
- VTL TL-65 Series II Signature line-stage and S-200 Signature power amplifier Reviewed in Issue 179
TL6.5 Series II and S-200 | HiFi+ (UK)
“The VTLs performance matches what is an expressive and dynamic tour de force. Repin and Argerich … their playing is at once intimately conjoined and dramatically bold. The VTLs paint a richly vivid musical picture, full of body and presence, light and shade. The instruments are held separate in space, with a beautifully natural sense of differential height and scale, surrounded by a convincing acoustic space. The connection between the musicians is as tangible and articulate as the interlocking phrases of the piece, sure sign that the amps have got the timing spot on.”“Spending time with these VTL amplifiers, it is easy to understand how and why the company has quietly but confidently established itself as the go-to option for versatile, high-powered tube amps. The TL-6.5 and S-200 don’t just tick the boxes – they own this turf!”
- Roy Gregory, “VTL TL-6.5 Series II Signature line-stage and S-200 Signature power amplifier”, Hi-Fi+ Issue 179, January 2020
TL6.5 Series II | The Audio Beat
“Put the latest ‘6.5 alongside the original version and what you’ll hear is a quieter, blacker background, deeper bass and crisper, quicker dynamics. Bottom-end pitch and textures are clearer, and the Series II throws a much more developed and clearly defined acoustic around and beyond the orchestra … Instrumental separation is better (tonally and spatially), while melodic lines are clearer and more fluid, that newfound clarity in the bass bringing organization and purpose to the midband and treble.”“This ability to cut to the musical core, to fasten on the expressive and emotive center in a recording — whether the recording itself is of audiophile grade or not – makes this a product for those with a genuine interest in and a system focused firmly on music.”
“The VTL TL-6.5 Series II doesn’t just take; it commands a place on the extremely short list of musically authoritative and satisfying one-box line stages”
- Roy Gregory, “VTL TL-6.5 Series II Signature Preamplifier,” April 30, 2018, TheAudioBeat.com
TL6.5 Series II | Audio Review (Italy)
“Conclusion” by Marco Benedetti
“I wonder too just because we know now for almost twenty years the seriousness with which Luke Manley and Bea produce their products; having already experienced the passage of 7.5 from Series II to III, I had a pretty good idea of what to expect; but, I repeat, the TL 6.5 II surprised me, the improvement over the old model goes beyond the most optimistic predictions, even reducing to a minimum the difference with more expensive and magical TL 7.5 III. VTL has struck again!”
“Listening” by M. Cives
If the previous (Series I) was a bargain at the time compared to the products of other vendors, this TL- 6.5 II brings the sound to realism due primarily to three parameters: rhythm, sound and spatial imaging. A revolution made by Luke Manley and Bea Lam for their wonderful, musical and technological products. To understand what a great step forward has been made, it should be pointed out the significant difference that exists between the two models being tested. In this listening sessions … was reinforced in me the idea of great seriousness of this product, In the case of VTL TL 6.5 II brought about a new standard for line preamplifiers, we’re on new parameters of sound reproduction that also differentiate them from the competition.”
- Marco Benedetti and M. Cives, “VTL TL6.5 II,” Audio Review Italy, 2017