Introducció
The Marshall SV20H Studio Vintage 20/5-watt Tube Head is a compact yet powerful amplifier designed to deliver the iconic "Plexi" tone. This amplifier head is a versatile tool for guitarists seeking classic British rock sounds, offering both 20-watt and 5-watt power modes for various playing environments, from studio recording to live performances. It features a 1-channel design with four inputs, high/low sensitivity loudness controls, an effects loop, and a power reduction circuit, providing flexibility and authentic vintagso.
Informació de seguretat
Please read and understand all safety instructions before operating the amplifier. Failure to follow these instructions may result in electric shock, fire, or other hazards.
- Font d'alimentació: Connecteu el amplifier only to a power supply of the type described in this manual and marked on the unit. Ensure the power cord is not damaged and is properly grounded.
- Ventilació: Do not block any ventilation openings. Install in accordance with the manufacturer's instructions. Adequate airflow is essential to prevent overheating.
- Aigua i humitat: Do not expose this apparatus to rain or moisture. Do not use near water or in wet locations.
- Calor: No instal·leu a prop de cap font de calor com ara radiadors, registres de calor, estufes o altres aparells (inclosos amplificadors) que produeixen calor.
- Manteniment: No intenteu fer la reparació d'aquest producte vosaltres mateixos. Envieu totes les tasques de manteniment a personal de servei qualificat. Cal fer la reparació quan l'aparell s'hagi fet malbé de qualsevol manera, com ara si el cable d'alimentació o l'endoll estan malmesos, si s'ha vessat líquid o si han caigut objectes a l'aparell, si l'aparell ha estat exposat a la pluja o la humitat, si no funciona correctament o si s'ha caigut.
- Tubs: Tub amplifiers contain vacuum tubes that operate at high temperatures and high voltages. Exercise extreme caution when handling or replacing tubes. Allow the amplifier to cool down completely before attempting any tube maintenance.
- Volum alt: L'exposició prolongada a nivells de volum elevats pot causar danys auditius permanents. Aneu amb compte a l'hora d'ajustar els nivells de volum.
Primers passos
Upon receiving your Marshall SV20H, carefully unpack the amplifier from its packaging. Retain all packaging materials for future transport or storage. Inspect the amplifier for any signs of damage that may have occurred during shipping. If any damage is found, contact your retailer immediately.
Abans de connectar el amplifier, ensure it is placed on a stable, level surface with adequate ventilation around all sides.
Configuració
Follow these steps to set up your SV20H amplifier head:
- Connect Speaker Cabinet: Using a high-quality speaker cable (not a guitar cable), connect the appropriate speaker output on the rear of the SV20H to your speaker cabinet. Ensure the impedance of the speaker cabinet matches the selected output on the amplifier (e.g., 8 Ohm output to an 8 Ohm cabinet). No feu servir mai el amplifier without a speaker load connected.
- Connectar l'alimentació: Assegureu-vos el amplifier's power switch is in the 'OFF' position. Connect the supplied power cord to the IEC inlet on the rear of the amplifier and then to a grounded electrical outlet.
- Connecteu l'instrument: Plug your guitar into one of the input jacks on the front panel. The SV20H features four inputs: two for High Sensitivity (Loudness 1) and two for Low Sensitivity (Loudness 2). Experiment to find the input that best suits your guitar and desired tone.

Figure 1: Front panel of the Marshall SV20H amplifier head, displaying the various controls and input jacks.
Funcionant el Ampmés viu
The SV20H offers intuitive controls for shaping your sound:
- Power Switch (MAINS): Gira el amplifier on and off. Always turn the amplifier on with the MAINS switch first, then the STANDBY switch (if applicable, though this model typically has a single power switch).
- Loudness 1 (High Sensitivity): Controls the volume of the high-sensitivity input. This input provides more gain and is ideal for achieving classic rock crunch and lead tones.
- Loudness 2 (Low Sensitivity): Controls the volume of the low-sensitivity input. This input offers cleaner tones with less gain, suitable for jazz, blues, or when using high-output pickups.
- Presència: Adjusts the amount of high-frequency feedback in the power amplifier section, adding sparkle and definition to your tone.
- Gravs, mitjans, aguts: Standard three-band equalizer controls to shape the low, mid, and high frequencies of your guitar tone.
- Power Reduction Circuit: The SV20H features a power reduction switch (often labeled 20W/5W or similar) allowing you to switch between full 20-watt output and a lower 5-watt output. This is useful for achieving cranked tube tones at lower volumes.
- Bucle d'efectes: The series effects loop (SEND/RETURN jacks on the rear panel) allows you to integrate external effects pedals (e.g., delay, reverb, modulation) into the amplifier's signal path after the preamp section. Connect the SEND to your pedal's input and the pedal's output to the RETURN.
Escalfament i refredament: Permet el amplifier a few minutes to warm up after turning it on before playing. Similarly, allow it to cool down for a few minutes after turning it off before moving it.
Manteniment
Proper maintenance will ensure the longevity and optimal performance of your SV20H ampmés viu:
- Neteja: Desconnecteu el amplifier from power before cleaning. Use a soft, dry cloth to wipe down the exterior. Do not use abrasive cleaners, solvents, or waxes.
- Substitució del tub: Vacuum tubes have a finite lifespan and will eventually need replacement. If you notice a decrease in performance, unusual noise, or a change in tone, it may be time to replace the tubes. Refer to a qualified technician for tube replacement, as this involves high voltages.
- Emmagatzematge: Quan no s'utilitzi durant períodes prolongats, guardeu-lo amplifier in a cool, dry place, ideally in its original packaging or a protective cover.
- Transport: Always disconnect all cables and allow the amplifier to cool down before transporting. Use appropriate cases or covers to protect the unit from physical damage.
Resolució de problemes
If you encounter issues with your SV20H, try these common troubleshooting steps:
| Problema | Causa possible | Solució |
|---|---|---|
| Sense so | Power not connected, speaker cable loose/incorrect, instrument cable faulty, volume knobs down. | Check power connection, ensure speaker cable is securely connected to correct impedance output, test instrument cable, increase Loudness controls. |
| So feble o distorsionat | Faulty tubes, incorrect speaker impedance, damaged speaker, effects loop issue. | Consult a technician for tube inspection/replacement. Verify speaker impedance. Test with a different speaker cabinet. Bypass effects loop to isolate issue. |
| Brunzit o soroll excessiu | Ground loop, faulty cable, proximity to other electronics, worn tubes. | Ensure proper grounding. Use shielded cables. Move amplifier away from power supplies or fluorescent lights. Consult technician for tube check. |
| Sense llum indicadora d'alimentació | Power cord disconnected, blown fuse, power outlet issue. | Check power cord connection. Replace fuse (refer to manual for fuse type and location, or consult technician). Test power outlet with another device. |
Si el problema persisteix després d'intentar aquestes solucions, poseu-vos en contacte amb personal de servei qualificat.
Especificacions
| Característica | Detall |
|---|---|
| Número de model | M-SV20H-U |
| Potència de sortidatage | 20 Watts (switchable to 5 Watts) |
| Canals | 1 (with 4 inputs: High/Low Sensitivity) |
| Controls | Loudness 1, Loudness 2, Presence, Bass, Middle, Treble |
| Bucle d'efectes | Yes (Series) |
| Font d'alimentació | Elèctric amb cable |
| Dispositius compatibles | Guitarra |
| Tipus de connector | Jack de 6.35 mm |
| Color | Negre |
| Pes de l'article | 25.3 lliures (11.48 kg) |
| Dimensions del producte (L x A x A) | 25 x 12 x 10 polzades (63.5 x 30.48 x 25.4 cm) |
| Data de primera disponibilitat | 24 de gener de 2019 |

Figure 2: Dimensions of the Marshall SV20H ampcap lifier.
Garantia i Suport
For information regarding warranty coverage and terms for your Marshall SV20H amplifier, please refer to the warranty card included with your product or visit the official Marshall Amplificació weblloc web. Conserveu el comprovant de compra per a reclamacions de garantia.
For technical support, service inquiries, or to locate an authorized service center, please contact Marshall Amplification customer support through their official weblloc web o la informació de contacte que es proporciona a la documentació del producte.
Official Marshall Weblloc: www.marshall.com





