VHT SPECIAL 6 ULTRA User manual
6-Watt Vacuum Tube High-Gain Guitar Amplier
User Manual
VHT SPECIAL 6
ULTRA
PRODUCT SAFETY INFORMATION.................1
OVERVIEW.............................................................2
FEATURES.............................................................3
CONTROL PANEL FUNCTIONS.....................4-5
REAR PANEL FUNCTIONS.............................6-7
BLOCK DIAGRAM................................................8
TONE CONTROL GRAPHS..........................9-12
DEPTH CONTROL GRAPH..............................13
TEXTURE CONTROL GRAPH.........................14
SCHEMATIC........................................................15
TECHNICAL SPECIFICATIONS......................16
TABLE OF CONTENTS
IMPORTANT SAFETY INSTRUCTIONS
1) Read these instructions.
2) Keep these instructions.
3) Heed all warnings.
4) Follow all instructions.
5) Do not use this amplifier near water.
6) Clean only with dry cloth.
7) Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
8) Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
9) Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A
grounding type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided
plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
10) Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from
the apparatus.
11) Only use attachments/accessories specified by the manufacturer.
12) Unplug this amplifier during lightning storms or when unused for long periods of time.
13) Refer all servicing to qualified service personnel. Servicing is required when the amplifier has been damaged in any way, such as power-
supply cord or plug is damaged, liquid has been spilled or objects have fallen into the amplifier, the amplifier has been exposed to rain or
moisture, does not operate normally, or has been dropped.
14) The amplifier shall not be exposed to dripping or splashing and no objects filled with liquids, such as vases, shall be placed on the amplifier.
15) This amplifier shall be connected to a mains socket outlet with a protective earthing connection.
16) The power/mains plug or amplifier coupler is the disconnect device which must remain readily operable.
WARNING To reduce the risk of fire or electric shock, do not expose this amplifier to rain or moisture.
VHT SPECIAL 6
ULTRA
MORE GAIN! MORE FEATURES! MORE FUN!
With its additional preamp gain stage, amazing power-attenuating Watts control, tube-driven effects loop, Line Out jack, 11-position Depth
control and 3-position Texture switch, the new high-gain Special 6 Ultra rockets the popular Special platform to the next level.
The Special 6 Ultra’s added gain stage provides plenty of overdrive for searing leads, bone-crushing crunch, and gristly grind, while its amaz-
ingly effective Watts control can reduce the volume to whisper-quiet bedroom practice levels — while maintaining the same overdriven tone,
texture and dynamic feel. We think you’ll agree — it’s truly amazing.
The Special 6 Ultra features the same unique Volume and Tone controls as the original Special 6, the same footswitchable Boost, High/Low
Power switch, and a similarly mod-friendly eyelet board.
The Special 6 Ultra also features a unique 11-position Depth control that ne-tunes the low-frequency depth and extension. Similarly, the 3-po-
sition Texture switch ne-tunes the high-frequency extension, harmonic content and texture. Inspired by vintage studio EQs like the legendary
Pultec EQP-1A, etc., these innovative tone-sculpting features allow you to precisely ne-tune the amp’s output stage frequency response and
character to perfectly suit a wide range of guitars, pickups, speakers, and musical styles — like a built-in post-production Pultec mastering EQ.
The Special 6 Ultra Combo and Head share the same chassis, circuit design, and component layout.
2
VHT 36W Handwired Head • Manual
1
123 5 7 8 10
4 6
11 129
1. Power Switch: This switch turns the amplier on or off.
2. High/Low Power and Standby switch: The Low-Power (triode mode) setting reduces the amplier’s maximum output power to approximately
one-half of the Full Power (pentode mode) setting. Low-Power mode produces a richer and smoother tone, with earlier breakup than High-
Power mode. The middle position is Standby mode.
3. Watts Control: The Watts control adjusts the output tube’s operating voltage and maximum output power. Maximum Output power ranges
from ½ watt (fully counterclockwise) to 6 watts (fully clockwise).
4. Jewel Light: This light will be illuminated when the Power switch is in the On position; the jewel light will be off when the Power switch is in
the Off position.
CONTROL PANEL FEATURES
VHT SPECIAL 6
ULTRA
FEATURES
6 Watts Maximum Output Power
One 6V6 Output Tube
Two 12AX7 Preamp Tubes
Ultra (high gain) and Clean Inputs
Ultra (high gain) Control
Volume and Tone Controls
Footswitchable Boost Mode
Tube-Driven Effects Loop
Tube-Driven Preamp Line Out
11-Position Depth Control
3-Position Texture Switch
High/Low Power Switch
Watts Control
12” VHT ChromeBack Speaker, 60-watt, 16 ohm (Combo Only)
Switchable 4, 8, or 16 Ohm Speaker Output
Mod-friendly Eyelet-Type Board
Hand-Wired in China
34
CONTROL PANEL FEATURES CONTINUED
5. Depth Control: This 11-position rotary switch selects the output tube’s low-frequency roll-off point. Set fully clockwise for the deepest low-
frequency extension. Lower settings (counterclockwise) expose more midrange texture and detail; the lowest settings emphasize more pres-
ence and bite.
6. Texture Switch: This 3-position rocker switch selects the output’s high-frequency roll-off point. The middle position provides maximum
top-end extension and the most harmonically complex texture; the left position provides subtle high-frequency roll-off for a slightly smoother
texture; the right position rolls-off more high frequencies for the smoothest texture.
7. Tone Control: This control adjusts the balance of the high and low frequencies.
8. Volume Control: Turning this knob clockwise increases the preamp drive and overall sound level. The Volume control is functional when
using either Clean or Ultra inputs.
9. Pull Boost: Pull this knob to partially bypass the internal tone shaping/voicing circuitry, which boosts the preamp gain and increases the
midrange emphasis. This feature can also be accessed by the footswitch.
NOTE: THE BOOST FOOTSWITCH WILL ONLY FUNCTION WHEN THE VOLUME KNOB IS IN THE PULLED POSITION.
10. Clean Input Jack: Use this input when cleaner lower-gain tones are desired. (When using the Clean input, turn the Ultra knob off to reduce
preamp noise.)
11. Ultra Control: This control adjusts the level of the extra gain (the Ultra control only functions when using the Ultra input).
12. Ultra Input Jack: This input engages the additional Ultra gain stage for maximum overdrive.
1 2 3 4 5 6
REAR PANEL FEATURES
1. Footswitch Jack: Plug the Boost footswitch into this jack.
NOTE: THE BOOST FOOTSWITCH WILL ONLY FUNCTION WHEN THE VOLUME KNOB IS IN THE PULLED POSITION.
s2. Effects Loop Send and Return Jacks: The post-preamp Effects Loop can accommodate a wide range of effects. The send level is depen-
dent on the preamp gain. High preamp gain levels may overdrive some sensitive guitar-level effects pedals.
3. Line Out Jack: The preamp Line Out is in parallel with the Effects Loop Send and Return jacks, it can be used to send a tube-buffered
low-impedance (unbalanced) signal to other equipment such as mixing consoles or other ampliers. Multiple Special 6 Ultra ampliers can be
linked by connecting the Line Out jack to the Effects Return of the second amplier. Several Special 6 Ultras can be linked in this manner, with
the rst amplier’s preamp serving as the master preamp for all additional ampliers.
5 6
Ultra Input V1A V1B
CleanUltra Level V2A V2B V3
Send Receive
Line Out
Depth Watts Texture SpeakerPull Boost Volume Tone
Tone Stack
BLOCK DIAGRAMREAR PANEL FEATURES CONTINUED
4. Impedance Selector: This 3-position slide switch selects the appropriate output impedance to match your speaker cabinet’s impedance.
5. Speaker Output Jacks: These two jacks are wired in parallel. The Special 6 Ultra combo has a 16-ohm speaker that is connected to the
internal speaker jack. The combo’s speaker remains connected when using the external Speaker Output jacks. When using the combo with an
additional speaker cabinet, switch the Impedance selector to 8 ohms.
6. Power IEC Receptacle: Use the included power cord with this unit in accordance with the AC line voltage and frequency ratings listed on
this manual and rear panel of this amplier. For lowest noise and safest operation, always provide the amplier with proper AC grounding.
78
TONE CONTROL - CLEAN INPUT (NO BOOST) TONE CONTROL - CLEAN INPUT (PULL BOOST)
9 10
-70
+10
-65
-60
-55
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
+0
+5
d
B
r
20 20k50 100 200 500 1k 2k 5k 10k
Hz
-70
+10
-65
-60
-55
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
+0
+5
d
B
r
TONE CONTROL - ULTRA INPUT (NO BOOST) TONE CONTROL - ULTRA INPUT (PULL BOOST)
11 12
-30
+20
-28
-26
-24
-22
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
+0
+2
+4
+6
+8
+10
+12
+14
+16
+18
d
B
r
20 20k50 100 200 500 1k 2k 5k 10k
Hz
-30
+20
-28
-26
-24
-22
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
+0
+2
+4
+6
+8
+10
+12
+14
+16
+18
d
B
r
DEPTH CONTROL
d
B
r
d
B
r
TEXTURE CONTROL
13 14
1 2 3 4 5 6 87
A
B
C
D
8
7654321
D
C
B
A
Title
Number:
RevisionSize
A3
Date: 3/10/2011
T
T NC
G NC
G
JK1
ULTRA
R1
68K
R2
1M
C2
101/500V
C5
10P/500V
C7
101/500V
C9
152/500V
C8
1u/100V
C6
222/630V
1
2
3
V1A
12AX7
C1
103/500V
R3
1K5
R4
100K
R49
10K
C3
22u/450V
C4
104/600V
R5
470K
R6
5.6K
1
2
3
VR1
1M
B+4
T
T NC
G NC
G
JK2
CLEAN
R8
33K
R7
1M
C11
101/500V
C12
10P/500V
C13
101/500V
C14
2u2/63V
6
7
8
V1B
12AX7
C10
103/500V
R9
1K5
R10
100K
B+4
C15
221/500V Mica (Cy2-2A)
C16
104/400V
C17
473/400V
R11
100K
R13
180K
R14
27K
R15
33K
R16
6K8
R12
68K
T
T NC
G NC
G
JK3
FOOT SWITCH
S1/VR1
1
2
3
VR2
1M
C18
471/500V Mica (Cy2-2A)
C19
103/630V
Push/Pull Pot
Push=Shunt (Clean)
Pull=NC (Boost)
1
2
3
VR3
1M
1
2
3
V2A
12AX7
R17
470K
R18
1K5
R19
100K
R20
1K5
R21
100K
R23
33K
C20
224/630V
T
T NC
G NC
G
JK4
SEND
T
T NC
G NC
G
JK5
RETURN
B+3
R22
1M
R25
220K
R24
1K5
6
7
8
V2B
12AX7
B+3
C22
4u7/63V
C21
103/500V
C23
472/400V
R38
5K6
R37
220K
R39
470R 5W
R40 470R 3W
D3 1N4007
D4
1N4007
S2
POWER SWITCH
F2
T6.3AL/250V SLOW BLOW
RED
RED
GREEN
GREEN
BLACKBLACK
BLACK
WHITE
WHITE
WHITE
YELLOW/GREEN
J3
J5
J4
J6
D1
IN4007
D2 IN4007
C35 8.2n/1KV
C36 8.2n/1KV
C38 8.2n/1KV
C37 8.2n/1KV
C48
0.1/630V
F1
T1AL/250V SLOW BLOW
BLACK
T1
RED
WHT
RT1
NTC(10R/5A)
NF72-10D15
AC
IEC
R41
470K
C39
47u/450V
C40
104/600V
R44
470K
R43
330R 5W
R45
100K
R46
100K
R42
10K
C45
22u/450V
C41
47u/450V
C43
22u/450V
C46
104/600V
C42
104/600V
C44
104/600V
T2Red
Blue
Black 0 ohm
B+1
Yellow 4 ohm
Brown 8 ohm
Orange 16 ohm
S3
STB FULL/HALF
TRIODE
STBY
PENTODE
ON
ON
STBY
1
2
3
VR4
1M
G
DS
Q1
MTP6N60E
B+3
R47
10R 5W R48
1K 3W
ZD1
12V 1W
B+2
BR1
25A
C47
12000u/16V
R52
220R
D5
LED (RED)
4
5
9
V1C
12AX7
4
5
9
V2C
12AX7
R26
1M
R27
1M
R28
1M
R29
1M
R30
1M
R31
1M
R32
1M
R33
1M
R34
1M
R35
1M
R36
1M
12" 16 OHMS
S1A S1B S1C S 1D S1E S1F S1G S1H S1I S 1J S1K
C24
224/100V
C25
334/100V
C26
474/100V
C27
684/100V
C28
1u/100V
C29
2u2/63V
C30
3u3/63V
C31
4u7/63V
C32
10u/63V
C33
15u/63V
C34
22u/63V
DEPTH
1P-11T ROTARY
SWITCH
Ceramic
Ceramic
FILM Ceramic Ceramic
FILM
Mica
CLEAN TONE
FILM
FILM
Ceramic
3
5
8
4
V3A
6V6GTW
2
7
V3B
6V6GTW
FILM
FILM
FILM
VHT Special 6 Ultra
Rev5.0
B+4
FILM FILM FILM FILM FILM
B+1
C49
472/400V
R50
100R
R51
100R
FILM
FILM
Mica
Mica
Mica
T
T NC
G NC
GJK6
LINEOUT
T
T NC
G NC
G
JK7
EXT SPK1
Ultra
8mVAC
TP1
220mVAC
TP3
300mVAC
TP8
300mVAC
TP7
300mVAC
TP9
1.5V DC
TP2
120mVAC
TP4
1.5V DC
TP5
104V DC
TP6
1.2V DC
TP10
19V DC
TP11
350V DC
TP13
288V DC
TP17
308V DC
TP16
326V to 26V DC
TP14
6.2V DC
TP18
6V AC
TP12
323V to 25V DC
TP15
S4
C50
2u2/100V (I)
C51
3u3/100V (II)
TEXTURE
FILM FILM
R54
15R 10W
C52
102/500V
C53
0.1/630V
T
T NC
G NC
G
JK8
EXT SPK2
T
T NC
G NC
G
JK9
INTERNALSPK
WATTS
F3
T0.5AL/250V SLOW BLOW
1,
(0.5W)
16ohm
8ohm
4ohm
TEST CONDITIONS:
1. WATTS & DEPTH TO MIN
2. TONE TO CENTER
3. ULTRA & CLEAN VOLUME TO MAX
TECHNICAL SPECIFICATIONS
Name/Model: VHT Special 6 Ultra
6-Watt High Gain Vacuum Tube Guitar Amplier / VHT Special 6 Ultra
Power Requirements & Consumption: 100/115VAC, 50/60Hz; 120VAC, 60Hz; 220VAC/230VAC240/VAC, 50/60Hz
Maximum Output Power: 6 watts
Speaker (combo only): One 12” VHT ChromeBack (60-watts, 16 ohms)
Amp Type: Hand-wired high-gain single-ended tube
Tubes: Two 12AX7; One 6V6
Controls: Ultra, Volume (with Pull-Boost), Tone, Texture, Depth, Watts, High/Low Power
Cabinet: Finger jointed birch plywood
Cosmetics: Black vinyl and black grille cloth
Dimensions (H x W x D): Combo: 18’’ x 19.5’’ x 10.5”
(457mm x 495mm x 267mm)
Head: 10.25” x 19.5’’ x 9.75’’
(257mm x 495mm x 250mm)
Net Weight: Head: 26.5 lbs. (12 kg)
Combo: 37.5 lbs. (17 kg)
15 16
Limited Warranty Information
This amplifier is warranted, to the original Purchaser, to be free from defects in material and workmanship for a period of five (5)
years, excluding the tubes and speaker, which are warranted for ninety (90) days, from the original date of purchase.
The manufacturer shall, at its option, either repair or replace the defective product if the product is returned to the original place
of purchase. If any product returned is not defective within this warranty, the manufacturer shall so advise the Purchaser and
thereafter shall dispose of said product in accordance with the Purchaser’s instructions and at the Purchaser’s cost. This warranty
is not transferable by the Purchaser.
The warranty shall not apply to wearable parts, these items include, but are not limited to, amplifier knobs, feet, and handles.
The warranty shall not apply, if the product has been misused or damaged as a result of neglect, abuse, alteration, improper
handling, unauthorized repair or modification, accident or causes external to the product, such as, but not limited to, excessive heat
or humidity.
The manufacturer’s sole and exclusive maximum liability for any claim by the Purchaser shall not exceed the wholesale
value of the product. In no event shall the manufacturer be liable for any indirect, incidental, collateral, exemplary, or
consequential damages of losses arising out of the Purchaser’s purchase of the product. The above limitations may not apply in
some states (U.S.), international regions or countries.
VHT
AMPLIFICATION
HAND-WIRED IN CHINA
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